FORTIFICATIONS.
_Fortifications, or engineering_, may be considered with reference to
the defence of states and the grand operation of armies; or with
reference to the details of the construction, and attack, and defence of
forts, and the influence of field-works on the tactical manoeuvres of
armies. It is proposed to speak here only of its general character, as a
branch of the military art, without entering into any professional
discussion of details.
The connection of fortification and strategy may be considered under two
distinct heads: 1st, the choice of sites for constructing fortresses for
defence; 2d, their influence in offensive operations, and the
determination of the question whether they can be passed with safety, or
whether the attacking force will be under the necessity of besieging
them.
The centre and extremities of _a base of operations_ should always be
secured either by natural or artificial obstacles. This base is
generally chosen so that fortifications will be necessary for
strengthening only a part of the line. But if a frontier, like the side
of France towards Belgium, be destitute of natural obstacles, the
artificial means of defence must be proportionally increased. Great care
should be taken that permanent fortifications be made only on such
places as may favor military operations. If otherwise, the troops
detached from the active army for garrisoning them, will only tend to
weaken this force without any corresponding advantages. In this way,
fortifications may become actually injurious to defence. A number of the
European fortresses which were built before the subject of strategy was
properly understood, are now regarded as utterly useless, from their
ill-advised positions.
Whether a fortress may be safely passed with merely blockading or
observing it, depends very much upon the nature of the war, and the
numbers and position of the defensive army. The allies, in 1814,
invading France with a million of soldiers, assisted by the political
diversion of factions and Bourbonists within the kingdom, and treason in
the frontier fortresses, and even in the ranks of Napoleon's army, could
conduct their military operations on a very different plan from that
which would be adopted by either Austria, Prussia, Russia, England,
Spain, Portugal, Holland, Italy, and the German powers, if singly waging
war with the French. Napoleon sometimes detached a corps to observe a
fortress which threatened his line of operations or of manoeuvre; at
others, he delayed his advance till the place could be reduced.
"An army," says Jomini, "may sometimes penetrate between places on an
open frontier, to attack the enemy's forces in the field, taking care at
the same time to _observe_ these places; but no invading army can cross
a great river, like the Danube, the Rhine, or the Elbe, without reducing
at least one of the fortresses on that river, so as to secure a line of
retreat; but being in possession of such a place, it can continue the
offensive, while its _matériel de siège_ successively reduces the other
places."
In case the main army is obliged to remain and cover the besieging
corps, it should take some central position, where it can command all
the avenues of approach, and fall with vigor on the enemy, should he
attempt to raise the siege. Napoleon's operations before Mantua, in
1796, offer the finest model for imitation.
The old system of intrenched camps and lines of contravallation is
unsuited to the spirit of modern warfare. In ancient times, and more
particularly in the middle ages, too much importance was attached to
tactical positions, and not enough to strategic points and lines. This
gave to fortifications a character that never properly belonged to them.
From the middle ages down to the period of the French Revolution, wars
were carried on mainly by the system of positions--one party confining
their operations to the security of certain important places, while the
other directed their whole attention to the siege and capture of these
places. But Carnot and Napoleon changed this system, at the same time
with the system of tactics, or rather, returned from it to the old and
true system of strategic operations. Some men, looking merely at the
fact that a _change_ was made, but without examining the _character_ of
that change, have rushed headlong to the conclusion that fortified
places are now utterly useless in war, military success depending
entirely upon a good system of marches.
On this subject, General Jomini, the great military historian of the
wars of the French Revolution, remarks that "we should depend entirely
upon neither organized masses, nor upon material obstacles, whether
natural or artificial. To follow exclusively either of these systems
would be equally absurd. The true science of war consists in choosing a
just medium between the two extremes. The wars of Napoleon demonstrated
the great truth, that distance can protect no country from invasion, but
that a state, to be secure, must have a good system of fortresses, and a
good system of military reserves and military institutions."
In all military operations _time_ is of vast importance. If a single
division of an army can be retarded for a few hours only, it not
unfrequently decides the fate of the campaign. Had the approach of
Blucher been delayed for a few hours, Napoleon must have been victorious
at the battle of Waterloo. An equilibrium can seldom be sustained for
more than six or seven hours between forces on the field of battle; but
in this instance, the state of the ground rendered the movements so
slow as to prolong the battle for about twelve hours; thus enabling the
allies to effect a concentration in time to save Wellington.
Many of Napoleon's brilliant victories resulted from merely bringing
troops to bear suddenly upon some decisive point. Rivoli in 1796-7,
Marengo in 1800, Ulm in 1805, Jena in 1806, Ratisbon in 1809, Brienne in
1814, and Ligny in 1815, are familiar examples. But this concentration
of forces, even with a regular army, cannot be calculated on by the
general with any degree of certainty, unless his communications are
perfectly secure. And this difficulty is very much increased where the
troops are new and undisciplined. When a country like ours is invaded,
large numbers of such troops must suddenly be called into the field. Not
knowing the designs of the invaders, much time will be lost in marches
and countermarches; and if there be no safe places of resort the
operations must be indecisive and insecure.
To a defensive army fortifications are valuable as points of repose,
upon which the troops, if beaten, may fall back, and shelter their sick
and wounded, collect their scattered forces, repair their materials, and
draw together a new supply of stores and provisions; and as rallying
points, where new troops may be assembled with safety, and the army, in
a few days, be prepared to again meet the enemy in the open field.
Without these defences, undisciplined and inexperienced armies, when
once routed, can seldom be rallied again, except with great losses. But
when supported by forts, they can select their opportunity for fighting,
and offer or refuse battle according to the probability of success; and,
having a safe place of retreat, they are far less influenced by fear in
the actual conflict.
The enemy, on the other hand, being compelled either to besiege or
_observe_ these works, his army will be separated from its magazines,
its strength and efficiency diminished by detachments, and his whole
force exposed to the horrors of partisan warfare. It has therefore been
estimated by the best military writers, that an army supported by a
judicious system of fortifications, can repel a land force _six_ times
as large as itself.
Every government should prepare, in time of peace, its most prominent
and durable means of defence. By securing in a permanent manner its
important points, it will enable a small force to retain possession of
these places against a greatly superior army, for a considerable length
of time. This serves the same purpose as a battle gained; for, in the
beginning of a war of invasion, the economy of time is of the utmost
importance to the defensive party, enabling it to organize and prepare
the great military resources of the state.
In all mountainous frontiers, or sides of states bordering on large
rivers, or chains of lakes, there will necessarily be but few points by
which an invader can penetrate into the interior of the country. Let us
suppose that, for a frontier of moderate extent, there are _five_
passes, or avenues through which the enemy may approach the interior. To
effectually defend these approaches against the invading army will
require, for each, an army of ten thousand men. Not being able to decide
positively on the plans of the enemy, all these communications must be
defended at the same time. This requires a defending army of fifty
thousand men. Let us now suppose each of these passes to be fortified in
such a way, that one thousand men will be able to hold the enemy in
check, and force him to resort to the operations of a siege; or, at
least, to retard his advance till an active army can be organized in the
interior, and prepared to meet him in the field. We here see that five
thousand men, by means of fortifications, can accomplish the same
defensive object as fifty thousand men without these artificial means of
security.
But let us enter a little more into the details of frontier defences,
and examine the character of the several systems which have been
successively proposed or adopted. Frontiers are divided into four
distinct classes, according as the state may be open on one or more
sides, or bounded by mountains, large rivers and lakes, or by the sea.
An open frontier is the most difficult of defence; and while there
exists a perfect uniformity among military men upon the vast importance
of fortifying such a frontier, there is an equal diversity of opinion
respecting the best manner of arranging these works. We shall here
mention three general systems of arranging forts for the defence of an
open country, each of which has been advocated at different times, and
afterwards received various modifications and additions. These three
systems comprise the main features of all others worthy of much
consideration. They are:--
1st. The system of continuous lines, proposed by Montalembert.
2d. A system of three lines of detached works, strongly recommended by
D'Arçon and others.
3d. A system proposed by Vauban, and advocated by Rogniat, consisting of
lines of very strong works, placed at considerable distances from each
other and covering large _intrenched camps_.
The first of these systems was proposed in 1790, and for a time
attracted considerable notice in France, but has long since been
discarded, as being utterly incompatible with the principles of the
military art. A writer, however, of some pretensions in this country,
recommends its adoption for the defence of Baltimore and the shores of
the Chesapeake. The same author would dispense entirely with our
present system of fortifications on the sea-coast, and substitute in
their place wooden Martello towers! This would be very much like
building 120 gun ships at Pittsburg and Memphis, for the defence of the
Ohio and the Mississippi rivers, and sending out duck-boats to meet the
enemy on the Atlantic!
In the second system, the works on the extreme frontier are to be placed
about thirty or forty miles apart, and those of the second and third
lines respectively thirty or forty miles in rear of the first and second
lines, and opposite the intervals.
In the third system, first recommended by Vauban and more recently by
Rogniat, the works are to be arranged in the same manner as in that of
D'Arçon, but the distance between them is to be from seventy to one
hundred miles, and each fort arranged for covering a large intrenched
camp.
Either of these last two systems is well suited to the defence of an
open frontier. The former is applied to the side of France towards
Belgium, and the latter, with certain modifications, to the defence of
Western Germany. The first line of fortifications on the northern
frontier of France consists of Dunkirk, Lille, Valenciennes, Condé,
Quesnoy, Rocroi, Charlemont, Mézières, and Sedan; the second line, of
Calais, Andres, St. Omer, Béthune, Arras, Douai, Chambrai, Landrecies,
and Avesnes; the third line, of Boulogne, Montreuil, Hesdin, Abbeville,
Amiens, Bapaume, Peronne, Ham, and Laon.
For mountainous frontiers it is deemed necessary to secure all the
important passes with small redoubts or military works, and to defend
with strong forts the grand interior strategic points on which these
communications are directed. For a frontier of moderate extent there may
be some six or eight gorges in the mountains by which an army might
penetrate; but it will always be found that these roads concentrate on
two or three points in the great valleys below. Take, for example, the
frontier of France towards Switzerland and Italy. The passes of the
mountains are secured by the little works of Fort L'Ecluse, Fort
Pierre-châtel, Fort Barraux, Briançon, Mont Dauphin, Colmars, Entrevaux,
and Antibes; while Besançon, Grenoble, and Toulon, form a second line;
and Lyons a grand central dépôt.
Where a great river or chain of lakes forms the boundary of a state, the
system of defence will be much the same as that of an open land
frontier, the works of the first line being made to secure the great
bridges or ferries by which the enemy might effect a passage; those of
the second line, to cover the passes of the highlands that generally
approach more or less near the great watercourse; and those of the third
line, far enough in rear to protect the great internal communications of
the country. Let us take, for example, the side of France bordering on
the Rhine. Wissembourg and Lauterbourg, Fort Louis, Haguenau,
Strasbourg, Schelstadt, Neuf-Brisach, and Huneguen, cover the several
passages of the river; while Bitche, Phalsbourg, and Béfort form a
second line; Thionville, Metz, and Toul, a third line; and Verdun a
grand central dépôt.
The following are the principal objects proposed to be accomplished by
fortifications on a sea-coast.
1st. To close all important harbors to an enemy, and secure them to the
navy of the country.
2d. To prevent the enemy from forming an establishment on our shores,
from which, by his naval superiority, he might destroy our commerce and
keep the whole frontier in continual alarm.
3d. To cover our great cities against a maritime attack and bombardment.
4th. To cover our ship-yards and great naval depots.
5th. To prevent, as much as possible, the great avenues of interior
navigation from being blockaded by naval means at their entrance into
the ocean.
6th. To give to our navy facilities for protecting our coast trade from
the enemy's ships of war, and our internal communications, which lie
near the coast, from maritime descents.
Let us notice how France has attempted to accomplish this object. The
Mediterranean frontier has Fort Quarré, Fort St. Marguérite, St. Tropez,
Brigançon, the forts of Point Man, of l'Ertissac, and of Langoustier,
Toulon, St. Nicholas, Castle of If, Marseilles, Tour de Boue,
Aigues-Montes, Fort St. Louis, Fort Brescou, Narbonne, Château de
Salces, Perpignan, Collioure, Fort St. Elme, and Port Vendre. Toulon is
the great naval dépôt for this frontier, and Marseilles the great
commercial port. Both are well secured by strong fortifications. The
Atlantic frontier has Bayonne; the forts of Royan, Grave, Medoc, Paté,
&c., on the Gironde; Rochefort, with the forts of Chapus, Lapin, Aix,
Oleron, &c., to cover the roadstead; La Rochelle, with the forts of the
Isle of Ré; Sables, with the forts of St. Nicholas, and Des Moulines,
Isle Dieu, Belle Isle, Fort du Pilier, Mindin, Ville Martin; Quiberon,
with Fort Penthièvre; L'Orient, with its harbor defences; Fort Cigogne;
Brest, with its harbor defences; St. Malo, with Forts Cézembre, La
Canchée, L'Anse du Verger, and Des Rimains; Cherbourg, with its
defensive forts and batteries; Havre, Dieppe, Boulogne, Calais, and
Dunkirk. Cherbourg, Brest, and Rochefort, are great naval dépôts; and
Havre, Nantes, and Bordeaux, the principal commercial ports. Many of the
works above enumerated are small in extent and antiquated in their
construction, and some of them quite old and dilapidated nevertheless,
they have heretofore been found sufficient for the defence of the naval
depots and commercial seaports of France against the superior naval
forces of her neighbor.
Omitting for the present all discussion of sea-coast defences, let us
examine more particularly the character and influence of fortifications
on land frontiers.
All military writers agree that fortifications have heretofore exerted a
great, and frequently a decisive, influence on the operations of a war.
Those of France are frequently referred to as proofs of this influence.
But, while all are disposed to allow that these works contributed much
in former times to the defence of states, yet some have said that modern
improvements in the mode of attack have rendered forts far less valuable
than formerly.
Such, however, is not the case. Improvements in the mode of attack have
not kept pace with the facilities of locomotion; and, although
fortifications do not now usually sustain a siege of as _many days_ as
in former times, still, as compared with the relative lengths of
campaigns in ancient and modern wars, the _proportional_ length of
sieges is now even _greater_ than formerly. When the same is
accomplished in a campaign of seven weeks as was formerly done in a war
of seven years, it is not necessary that fortified places should hold
out a very long time. A place that can sustain a siege of a month is now
deemed sufficiently strong for ordinary campaigns; for by the end of
that time the defensive army will either be destroyed, or be able to
come to its succor. In either case a longer defence would not be
required.
A reference to the most important sieges of the last century or two will
show that forts are, on an average, capable of sustaining a siege for
more than that length of time. Lille, in 1708, held the allies in check
for a whole year; and again, in 1792, compelled the Austrians to raise
the siege after an unsuccessful attack of fifteen days.
Antwerp, in 1585, sustained a siege of fourteen months against greatly
superior forces; in 1814 Carnot defended the citadel of this place for
four months, and until an armistice had been concluded between the
contending parties; in 1832, it sustained, with a garrison of only 4,500
men and 145 pieces of ordnance, a siege of twenty-five days, against a
force of 55,000 men and 223 cannon.
Namur, near the end of the seventeenth century, sustained a siege of ten
weeks.
Ismaïl, in 1790, sustained a siege of more than two months against the
Russians.
Maestricht, in 1793, sustained a siege of nearly two weeks; and again,
in 1794, sustained a blockade and siege of nearly two months.
Magdeburg, in the thirty years' war, resisted the army of Wallenstein
for seven months; and in 1813-14, although garrisoned by only 4,000 men,
it for a long time resisted the overwhelming forces of the allies.
Dantzic, at the same time, sustained a siege against superior forces for
more than nine months.
Landau, in 1793, sustained a siege of nine months.
Valenciennes and Mayence, in 1793, each sustained a siege of about three
months.
Charleroi, Fort Vauban, and L'Ecluse, in 1794, each sustained a siege of
about thirty days.
Quesnoy, in 1794, sustained a siege of about three weeks.
Rosas, in 1795, sustained a siege of some seventy days.
Mantua, in 1796-7, protected from invasion, for eight months, the Tyrol
and the heart of the Austrian monarchy.
Kehl and Huninguen, in 1796, sheltered Moreau for three months against
all the efforts of the Archduke Charles.
St. Jean d'Acre, in 1799, sustained a siege of sixty days of open
trench.
Ulm, in 1800, held Moreau in check for more than a month.
Genoa, in 1800, sustained a blockade of sixty and a siege of forty days.
Saragossa in 1808 sustained a close siege of near two months; and in
1809 it was again besieged for two months.
Rosas in 1808 sustained a siege of thirty days.
Gerona in 1809 sustained a siege and blockade of seven months, nearly
four of them being of open trench.
Mequinenza (a very small work) in 1810 sustained a siege of more than
two weeks.
Astorga in 1810 sustained a siege of thirty days; twenty-four being of
open trench.
Lerida in 1810 sustained a siege of thirty days, two weeks being of open
trench.
Ciudad Rodrigo in 1810 sustained a siege of two months.
Almeida in 1810 sustained a siege of more than a month.
Tortosa in 1810 sustained a siege of six months.
Tarragona in 1811 sustained a siege of nearly two months.
Badajos in 1811 sustained a siege of more than forty days open trench.
Lerida in 1811 sustained a siege of two weeks open trench.
Saguntum in 1811 sustained a siege of a month.
Valencia in 1811-12 sustained a siege of two months
Ciudad Rodrigo in 1812 sustained a blockade of several months, and a
close siege of two weeks.
Badajos in 1812 sustained twenty-one days of open trenches.
Burgos in 1812 sustained thirty-three days of open trenches.
St. Sebastian in 1813 sustained a siege and blockade of nearly three
months, with fifty-nine days of open trenches.
Pampeluna in 1813 sustained a siege of more than four months.
Monzon in 1813-14 also sustained a siege of more than four months.
This list might be increased with numerous other examples, to show that
even poorly fortified towns are capable of defending themselves, on an
average, for more than a month. These examples, be it remembered, are
nearly all taken from a period of history since any material
improvements have been made in the art of attack. Since the time of
Vauban the improvements in attack have not kept pace with the increased
means of defence. Moreover, these examples are taken from the sieges of
towns defended mainly by old and antiquated works, and entirely
incapable of offering the same resistance as detached fortifications,
with all the modern improvements.
The value of fortifications, as land defences, is sufficiently proved by
showing their general capability of resisting an invader, even for a
limited period; thus affording us time and opportunity to provide other
means of security. But it must not be inferred that forts besieged _en
règle_ will necessarily fall after so many days. Such is far from being
the case. The besieged have usually great advantages over the besiegers;
and unless the latter are vastly superior in number, or the work is of a
very inferior character, or the garrison is destitute of the requisite
means and energy to resist an attack, they will not be taken.
Mezieres was not taken in 1520; nor Marseilles in 1524; nor Peronne in
1536; nor Landrecies in 1543; nor Metz in 1552; nor Montauban in 1621;
nor Lerida in 1647; nor Maestricht in 1676; nor Vienna in 1529, and
again in 1683; nor Turin in 1706; nor Conde in 1744; nor Lille in 1792;
nor Landau in 1793; nor Ulm in 1800; nor Saragossa in 1808; nor Burgos
in 1812. This list might be extended almost indefinitely with the names
of places that could be reduced neither by force nor by starvation.
But, as has already been noticed, some have asserted that fortifications
have become of little comparative importance, under the new system of
warfare introduced during the wars of the French Revolution. On this
subject let us consult the opinions of the best military judges of the
present century.
Napoleon says of fortifications, "they are an excellent means of
retarding, fettering, enfeebling, and disquieting a conquering foe."
"The possession of strategic points," says the Archduke Charles, "is
decisive in military operations; and the most efficacious means should,
therefore, be employed to defend points whose preservation is the
country's safeguard. This object is accomplished by fortifications,
inasmuch as they can resist, for a given time, with a small number of
troops, every effort of a much larger force; fortifications should,
therefore, be regarded as the basis of a good system of defence." "It
should be a maxim of state policy in every country, to fortify, in time
of peace, all such points, and to arrange them with great care, so that
they can be defended by a small number of troops. For the enemy, knowing
the difficulty of getting possession of these works, will look twice
before he involves himself in a war." "Establishments which can secure
strategic advantages are not the works of a moment; they require time
and labor. He who has the direction of the military forces of a state,
should, in time of peace, prepare for war." "The proper application or
neglect of these principles will decide the safety or the ruin of the
state." "Fortifications arrest the enemy in the pursuit of his object,
and direct his movements on less important points;--he must either force
these fortified lines, or else hazard enterprises upon lines which offer
only disadvantages. In fine, a country secured by a system of defences
truly strategic, has no cause to fear either the invasion or the yoke of
the enemy; for he can advance to the interior of the country only
through great trouble and ruinous efforts. Of course, lines of
fortifications thus arranged cannot shelter a state against all reverses;
but these reverses will not, in this case, be attended by total ruin;
for they cannot take from the state the means nor the time for
collecting new forces; nor can they ever reduce it to the cruel
alternative of submission or destruction."
"Fortifications," says Jomini, "fulfil two objects of capital
importance,--1st. The protection of the frontiers; and 2d. Assisting the
operations of the army in the field." "Every part of the frontiers of a
state should be secured by one or two great places of refuge, secondary
places, and even small posts for facilitating the active operations of
the armies. Cities girt with walls and slight ditches may often be of
great utility in the interior of a country, as places of deposit, where
stores, magazines, hospitals, &c., may be sheltered from the incursions
of the enemy's light troops. These works are more especially valuable
where such stores, in order not to weaken the regular army by
detachments, are intrusted to the care of raw and militia forces." It is
not supposed that any system of fortifications can hermetically close a
frontier; "but, although they of themselves can rarely present an
absolute obstacle to the advance of the hostile army, yet it is
indisputable that they straiten its movements, change the direction of
its marches, and force it into detachments; while, on the contrary, they
afford all the opposite advantages to the defensive army; they protect
its marches, favor its debouches, cover its magazines, its flanks, and
its movements, and finally furnish it with a place of refuge in time of
need."
These opinions were uttered, be it remembered, long since the period at
which modern military quacks date the downfall of fortifications as
inland defences, by men, too, who were not engineers, and consequently
had no professional predilections in favor of fortifications. The
Archduke Charles, as a general, knew no rival but Napoleon, and General
Jomini is universally regarded as the first military historian of the
age. The truth of their remarks on fortifications is most fully
confirmed by the military histories of Germany and France.
For a long period previous to the Thirty Years' War, its strong castles
and fortified cities secured the German empire from attacks from abroad,
except on its extensive frontier, which was frequently assailed, but no
enemy was able to penetrate to the interior till a want of union among
its own princes opened its strongholds to the Swedish conqueror; nor
then, did the cautious Gustavus Adolphus venture far into its
territories till he had obtained possession of all the military works
that might endanger his retreat.
Again, in the Seven Years' War, when the French neglected to secure
their foothold in Germany, by placing in a state of defence the
fortifications that fell into their power, the first defeat rendered
their ground untenable, and threw them from the Elbe back upon the Rhine
and the Mayne. They afterwards took the precaution to fortify their
positions, and to secure their magazines under shelter of strong places,
and, consequently, were enabled to maintain themselves in the hostile
country till the end of the war, notwithstanding the inefficiency of
their generals, the great reverses they sustained in the field, the
skill and perseverance of the enemy they were contending with, and the
weak and vacillating character of the cabinet that directed them.
But this system of defence was not so carefully maintained in the latter
part of the eighteenth century, for at the beginning of the French
Revolution, says Jomini, "Germany had too few fortifications; they were
generally of a poor character, and improperly located." France, on the
contrary, was well fortified: and although without armies, and torn in
pieces by domestic factions, (we here use the language of the Archduke,)
"she sustained herself against all Europe; _and this was because her
government, since the reign of Louis XIII_., _had continually labored to
put her frontiers into a defensive condition agreeably to the principles
of strategy_; starting from such a system for a basis, she subdued every
country on the continent that was not thus fortified; and this reason
alone will explain how her generals sometimes succeeded in destroying an
army, and even an entire state, merely by a strategic success."
This may be illustrated by reference to particular campaigns. In 1792,
when the Duke of Brunswick invaded France, she had no armies competent
to her defence. Their numbers upon paper were somewhat formidable, it is
true, but the license of the Revolution had so loosened the bonds of
discipline as to effect an almost complete disorganization. "It seemed,
at this period," says the historian, "as if the operations of the French
generals were dependent upon the absence of their enemies: the moment
they appeared, the operations were precipitately abandoned." But France
had on her eastern frontier a triple line of good fortresses, although
her miserable soldiery were incapable of properly defending them. The
several works of the first and second lines fell, one after another,
before the slow operations of a Prussian siege, and the Duke of
Brunswick was already advancing upon the third, when Dumourier, with
only twenty-five thousand men, threw himself into this line, and by a
well-conducted war of positions, placing his raw and unsteady forces
behind unassailable intrenchments, succeeded in repelling a disciplined
army nearly four times as numerous as his own. Had no other obstacle
than the French troops been interposed between Paris and the Prussians,
all agree that France must have fallen.
In the campaign, of 1793, the French army in Flanders were beaten in
almost every engagement, and their forces reduced to less than one half
the number of the allies. The French general turned traitor to his
country, and the National Guards deserted their colors and returned to
France. The only hope of the Republicans, at this crisis, was Vauban's
line of Flemish fortresses. These alone saved France. The strongholds of
Lille, Condé, Valenciennes, Quesnoy, Landrecies, &c., held the Austrians
in check till the French could raise new forces and reorganize their
army. "The important breathing-time which the sieges of these
fortresses," says an English historian, "afforded to the French, and the
immense advantage which they derived from the new levies which they
received, and fresh organization which they acquired during that
important period, is a signal proof of the vital importance of
fortresses in contributing to national defence. Napoleon has not
hesitated to ascribe to the three months thus gained the salvation of
France. It is to be constantly recollected that the Republican armies
were then totally unable to keep the field; that behind the frontier
fortresses there was neither a defensive position, nor a corps to
reinforce them; and that if driven from their vicinity, the capital was
taken and the war concluded."
In the following year, 1794, when France had completed her vast
armaments, and, in her turn, had become the invading power, the enemy
had no fortified towns to check the progress of the Republican armies;
which, based on strong works of defence, in a few weeks overran
Flanders, and drove the allies beyond the Rhine.
In the campaign of 1796, when the army of Moreau had been forced into a
precipitate retreat by the admirable strategic operations of the
Archduke Charles, the French forces owed their safety to the
fortifications on the Rhine. These works arrested the enemy's pursuit
and obliged him to resort to the tedious operations of sieges; and the
reduction of the French advanced posts alone, Kehl and Huninguen, poorly
as they were defended, employed all the resources of the Austrian army,
and the skill of their engineers, from early in October till late in
February. Kehl was at first assaulted by a force _four_ times as
numerous as the garrison; if the enemy had succeeded, he would have cut
off Moreau's retreat, and destroyed his army. Fortunately the place was
strong enough to resist all assaults; and Moreau, basing himself on the
fortresses of Alsace, his right covered by Huninguen, Neuf-Brisach, and
Béfort, and his left by the iron barrier of the Netherlands, effectually
checked the waves of Austrian success.
Let us now turn to the campaigns of Napoleon. In his first campaign in
Italy, 1796, the general was directed "to seize the forts of Savona,
compel the senate to furnish him with pecuniary supplies, and to
surrender the keys of Gavi, a fortress perched on the rocky height
commanding the pass of the Bocchetta." Setting out from Savona, he
crossed the mountains at a weak point between the Alps and the
Apennines, and succeeded in piercing the enemy's line of defence. The
king of Sardinia, jealous of Austrian influence, had refused to permit
the Austrian army to garrison his line of fortifications. Napoleon,
profiting by his victorious attitude, the mutual jealousy of Austria
and Sardinia, and the intrigues of his diplomatists, soon gained
possession of these important works. "_These Sardinian fortresses_," he
wrote to the Directory, "_at once put the Republicans in possession of
the keys of the Peninsula_." Basing himself on Coni, Mondovi, Ceva,
Gavi, and Alessandria, with Tortosa as his dépôt of magazines, he
advanced against Lombardy. Now basing himself on the Adda and Po, with
the fortress of Pizzighettone as the dépôt of his magazines, he advanced
upon the line of the Adige. Pechiera became his next dépôt, and he now
had four fortresses in echelon between him and his first dépôt of
magazines; and, after the fall of Mantua, basing himself on the Po, he
advanced against the States of the Church, making Ferrara and then
Ancona, his places of dépôt.
From the solid basis of the fortresses of Piedmont and Lombardy, "he was
enabled to turn his undivided attention to the destruction of the
Austrians, and thus commence, with some security, that great career of
conquest which he already meditated in the imperial dominions." In this
campaign of 1797, after scouring his base, he fortified Palma-Nuova,
Osapo, &c., repaired the old fortifications of Klagenfurth, and, as he
advanced, established, to use his own words, "a good _point d'appui_ at
every five or six marches."
Afterwards, when the Austrians had nearly wrested Italy from the weak
grasp of Napoleon's successors, the French saved their army in the
fortress of Genoa and behind the line of the Var, which had been
fortified with care in 1794-5. Numerous attempts were made to force this
line, the advanced post of Fort Montauban being several times assaulted
by numerous forces. But the Austrian columns recoiled from its murderous
fire of grape and musketry, which swept off great numbers at every
discharge. Again the assault was renewed with a vast superiority of
numbers, and again "the brave men who headed the column almost perished
at the foot of the intrenchment; and, after sustaining a heavy loss,
they were compelled to abandon the enterprise."
While the forces on the Var thus stayed the waves of Austrian success,
Massena, in the fortifications of Genoa, sustained a blockade of sixty,
and a siege of forty days, against an army five times as large as his
own; and when forced to yield to the stern demands of famine, he almost
dictated to the enemy the terms of the treaty. These two defences held
in check the _élite_ of the Austrian forces, while the French reserve
crossed the Alps, seized the important points of the country, and cut
off the Austrian line of retreat. "But even after the victory of
Marengo," says Napoleon, "I did not consider the whole of Italy
reconquered, until all the fortified places between me and the Mincio
should be occupied by my troops. I gave Melas permission to return to
Mantua, on condition of his surrendering all these fortresses."
He now directed Chasseloup de Laubat and his engineers to repair and
remodel the fortifications of Verona, Legnano, Pechiera, Mantua, the
line of the Adda, Milan, Alessandria,[5] Roco d'Aufo, Genoa, and several
smaller works; thus forming a quadruple line of defence against Austrian
aggression in Italy. These works were of great service to the French in
1805, enabling Massena with fifty thousand men to hold in check the
Archduke Charles with more than ninety thousand, while Napoleon's grand
army, starting from the solid base of the Rhine, traversed Germany and
seized upon the capital of Austria.
[Footnote 5: More than twenty millions of money were appropriated for
this place alone.]
The neglect of the Prussians to place their country in a state of
military defence, previous to declaring war against Napoleon in 1806,
had a most disastrous influence upon the campaign. Napoleon, on the
other hand, occupied and secured all the important military positions
which he had captured in the preceding campaign. "The Prussians," said
he, "made no preparations for putting into a state of defence the
fortifications on their first line, not even those within a few marches
of our cantonments. While I was piling up bastion upon bastion at Kehl,
Cassel, and Wesel, they did not plant a single palisade at Magdeburg,
nor put in battery a single cannon at Spandau." The works on the three
great lines of the Oder, the Elbe, and the Weser, had they been properly
repaired, garrisoned, and defended, were sufficient to have held in
check the French, even after the great victory of Jena, till the
newly-organized forces, acting in concert with the Russian army, could
re-establish the Prussian monarchy in its ancient greatness. Profiting
by the neglect of the Prussians, Napoleon seized upon the great
defensive works of the country, which, to his great joy, were readily
surrendered into his hands by the old and inefficient generals who
commanded them; and French garrisons were almost immediately established
in the fortresses of Stettin, Custrin, Glogau, Magdeburg, Spandau,
Hameln, Nieubourg, &c. "Spandau," said he in the 19th Bulletin, "is an
inestimable acquisition. In our hands it could sustain two months of
operations. But such was the general confusion, that the Prussians had
not even armed its batteries." The possession of these fortifications
inclined the scale at Eylau. All the historians of the war notice their
influence on the campaigns of Friedland and Tilsit.
These Prussian fortresses were retained by Napoleon at the treaty of
Tilsit. The campaign of 1809 proved the wisdom of this policy, as they
effectually prevented Prussia from joining Austria in rekindling the
flames of war. And again in 1813, these works might have produced a
decided influence on the campaign, had not the political perfidy of
Austria, and the treason of the French generals, prevented Napoleon from
profiting by the advantages of his position.
The influence of the fortifications of Spain upon the Peninsular
campaigns has often been alluded to by historians. Those works which had
been given up to Napoleon previous to the opening of hostilities,
contributed very much to the success of his arms; while those which had
been retained by Spain and her allies contributed in an equal degree to
fetter and embarrass his operations. Some of these, like Saragossa,
Tarragona, Gerona, Tortosa, &c. &c., with their broken walls and
defective armaments, kept the enemy in check for months; and, by
compelling the French to resort to the tedious operations of sieges, did
much to weaken the French power in the Peninsula.
The influence of the fortifications of the French frontiers in
furnishing a secure basis for the successful operations of Napoleon into
the enemy's territory, has already been noticed. If these fortresses of
France, after the disasters of 1812 and '13, failed to save the nation,
the cause must be sought for in the peculiar features of the invasion
itself, rather than any lack of military influence in the French
defences. As has been already remarked, a million of disciplined men,
under consummate leaders, were here assailing a single state,
impoverished by the fatal war in Russia,--torn in pieces by political
factions,--deserted by its sworn allies,--its fortresses basely betrayed
into the enemy's hands, and its military power paralyzed by the treason
of generals with their entire armies. Its only hope was in the
fortresses which had remained faithful; and Napoleon said at St. Helena,
that if he had collected together the garrisons of these few fortresses
and retired to the Rhine, he could have crushed the allies even after
their entrance into Paris. But political considerations prevented the
operation.
Again in 1815, Napoleon, even after the defeat of Waterloo, possessed
lines of defence sufficiently strong to resist all attempts at invasion.
But again the want of co-operation on the part of the government at
Paris, and the treason of his own generals, forced his second
abdication. If he had retained the command of the army, and the nation
had seconded his efforts, the allies would never have reached Paris. But
the new government presented the disgraceful spectacle of opening the
way for the enemies of their country. "France," said Napoleon, "will
eternally reproach the ministry with having forced her whole people to
pass under the Caudine-forks, by ordering the disbanding of an army that
had for twenty-five years been its country's glory, _and by giving up to
our astonished enemies our still invincible fortresses_."
History fully supports Napoleon's opinion of the great danger of
penetrating far into a hostile country to attack the capital, even when
that capital is without fortifications. The fatal effects of such an
advance, without properly securing the means of retreat, is exemplified
by his own campaign of 1812, in Russia. If, after the fall of Smolensk,
he had fortified that place and Vitepsk, which by their position closed
the narrow passage comprised between the Dnieper and the Dwina, he might
in all probability, on the following spring, have been able to seize
upon Moscow and St. Petersburg. But leaving the hostile army of
Tschkokoff in his rear, he pushed on to Moscow, and when the
conflagration of that city cut off his hopes of winter quarters there,
and the premature rigor of the season destroyed the horses of his
artillery and provision-trains, retreat became impossible, and the awful
fate of his immense army was closed by scenes of horror to which there
is scarcely a parallel in history. This point might be still further
illustrated by the Russian campaign of Charles XII., in 1708-9, the
fatal advance of the French army on Lisbon, in the Peninsular war, and
other examples of the same character.
Even single works sometimes effect the object of lines of
fortifications, and frustrate the operations of an entire army. Thus,
Lille suspended for a whole year the operations of Prince Eugene and
Marlborough; the siege of Landrecies gave Villars an opportunity of
changing the fortunes of the war; Pavia, in 1525, lost France her
monarch, the flower of her nobility, and her Italian conquests; Metz, in
1552, arrested the entire power of Charles V., and saved France from
destruction; Prague, in 1757, brought the greatest warrior of his age to
the brink of ruin; St. Jean d'Acre, in 1799, stopped the successful
career of Napoleon; Burgos, in 1812, saved the beaten army of Portugal,
enabled them to collect their scattered forces, and regain the
ascendancy; Strasburg has often been, the bulwark of the French against
Germany, saving France from invasion, and perhaps subjugation.
In nearly the language of Napoleon, (Memoirs, vol. IX.,) If Vienna had
been fortified in 1805, the battle of Ulm would not have decided the
fate of the war. Again, in 1809, if this capital had been fortified, it
would have enabled the Archduke Charles, after the disaster of Eckmuhl,
by a forced retreat on the left of the Danube, to form a junction with
the forces of General Hiller and the Archduke John.
If Berlin had been fortified in 1806, the army routed at Jena would have
rallied there and been joined by the Russians. If Madrid had been
strongly fortified in 1808, the French army, after the victories of
Espinosa, Tudela, Burgos, and Sommo-Sierra, would not have marched
towards that capital, leaving in rear of Salamanca and Valladolid, both
the English army of General Moore and the Spanish army of Romana. If
Moscow had been fortified in 1812, its conflagration would have been
avoided, for, with strong defensive works, and the army of Kutusoff
encamped on its ramparts, its capture would have been impossible.
Had not Constantinople been well fortified, the empire of Constantine
must have terminated in the year 700, whereas the standard of the
Prophet was not planted there until 1440. This capital was therefore
indebted to its walls for eight hundred years of existence. During this
period it was besieged fifty-three times, but only one of these sieges
was successful. The French and Venetians took it, but not without a very
severe contest.
Paris has often owed its safety to its walls. In 885 the Normans
besieged it for two years without effect. In 1358 the Dauphin besieged
it in vain. In 1359 Edward, king of England, encamped at Montrouge,
devastated the country to its walls, but recoiled from before it, and
retired to Chartres. In 1429 it repulsed the attack of Charles VII. In
1464 the Count of Charlerois surrounded the city, but was unsuccessful
in his attacks. In 1472 it repulsed the army of the Duke of Bourgone,
who had already ravaged its precincts. In 1536, when attacked by Charles
V., it again owed its safety to its walls. In 1588 and 1589 it repulsed
the armies of Henry III. and Henry IV. In 1636 and several succeeding
years the inhabitants of Paris owed their safety to its walls. If this
capital had been strongly fortified in 1814 and 1815, the allied armies
would not have dared to attempt its investment.
But it is deemed unnecessary to further specify examples; the whole
history of modern warfare is one continued proof of the importance of
fortifications as a means of national defence, and as an auxiliary in
offensive military operations. Our illustrations have been mostly drawn
from European wars, but our own brief history, as will be shown
hereafter, is not without its proofs.
The use and importance of field-fortifications, intrenched camps, &c.,
as well as the class of military works called coast-defences, will be
discussed hereafter.[6]
[Footnote 6: The use of fortifications in the defence of states is
discussed by Ternay, Vauban, Cormontaigne, Napoleon, the Archduke
Charles, Jomini, Fallot, and, incidentally, by most of the military
historians of the wars of the French Revolution. The names of such
standard works as give the detailed arrangements of fortifications will
be mentioned hereafter.]