In like manner, when the northern tribes of Europe overran the Roman
Empire, they found themselves, in some measure, shut out from Britain
by its wall of sea. The Jutes, Saxons, and Angles could not enter it
in countless hordes, but only in small numbers and by occasional
attacks. Because of this, the invaders could only drive back the
Britons by slow degrees, and they never entirely crushed them.
Again, the conquerers could not build up a strong, united kinigdom,
but they had to content themselves with establishing a number of petty
kingdoms which were constantly at war with each other. Later, the
whole of England became subject to a sing sovereign. But the chief
men of the separate kingdoms, which had now become simply shires or
counties, retained a certain degree of control over the government.
This prevented the royal power from becoming the unchecked will of an
arbitrary ruler. Finally, it may be said that the isolation of
England had much to do with the development of the strong individual
character of its people.