As we had Kings of England of the name of Edward before the Conquest,
Edward the First was distinguished from these monarchs by being styled
"King Edward, the son of King Henry" (his father was called "King Henry,
the son of King John"). In like manner, Edward II. was distinguished from
his father by being called "King Edward, the son of King Edward;" but
Edward III. could not thus be distinguished from his father; he was
therefore called King Edward III.; but, as there were Kings Edward _before_
the Conquest, the third was qualified by the addition of the phrase in
question, "post conquestum." To Richard II. generally, and to his
successors up to Henry VIII. either generally or occasionally, the same
phrase, "post conquestum," was also applied; but, if we except Edward IV.
and V., this phrase was not at all required, or applicable in their cases,
inasmuch as no King of England _before_ the Conquest was named either
Richard or Henry.