paladin (n.)

1590s, in reference to the medieval romance cycle, "one of the twelve knightly champions in attendance on Charlemagne and accompanying him to war," from Middle French paladin "a warrior" (16c.), from Italian paladino, from Latin palatinus "palace official;" noun use of palatinus "of the palace" (see palace).

The Old French form of the word was palaisin (which gave Middle English palasin, c. 1400); the Italian form prevailed because, though the matter was French, most of the poets who wrote the romances were Italians. Extended sense of "a heroic champion" is by 1788.