The Bulfinch Encyclopedia of Mythology states that the twelve most illustrious knights of Emperor Charlemagne of the Holy Roman Empire were called Paladins. Lois McMaster Bujold took this term and applied it to the hero of her 2003 book, The Paladin of Souls, for which she got her fourth Hugo Award.
Paladin of Souls is a fantasy work set in Chalion, a land where religious practice is split among the Five Gods: Father of Winter, Mother of Summer, Son of Autumn, Daughter of Spring, and the Bastard (God of Death). The Five Gods put a curse on Chalion a long time back, and people still suffer from the after-effects. The mythological world-building in this book is absolutely gripping.
