_Christian Names_ (Vol. vii., p. 406.).--When Lord Coke says "a man cannot
have two names of baptism, as he may have divers surnames," he does not
mean that a man may not have two or more Christian names given to him at
the font, but that, while he may have "divers surnames at divers times," he
may not have divers Christian names _at divers times_.
When a man changes his Christian name, he alters his legal identity. The
surname, however, is assumable at pleasure. The use of surnames came into
England, according to Camden, about {489} the time of the Conquest, but
they were not in general use till long after that. Many branches of
families used to substitute the names of their estate or residence for
their patronymic, which often makes the tracing of genealogies a difficult
matter. It was not till the middle of the fourteenth century that surnames
began to descend from father to son, and a reference to any old document of
the time will show how arbitrarily such names were assumed.
A surname, in short, may be called a matter of convenience; a Christian
name, a matter of necessity. The giving two Christian names at baptism did
not come generally into use till, owing to the multiplication of the
patronymic, a single Christian name became insufficient to identify the
individual. Consequently an instance of a double Christian name, previous
to the commencement of the eighteenth century, is a rarity. The fifth and
sixth earls of Northumberland bore the names of Henry-Algernon Percy. The
latter died in 1537.
As to the period at which Christian names were assumed as surnames, your
correspondent ERICAS is referred to Lower's _English Surnames_.