system
Given the following post, respond as if you're commenting on Reddit:
human
[General] From where or when did the class/title of Paladin develop?
gpt
The Paladins were another name for the Twelve Peers-- basically, like the Knights of the Round Table, except there were only 12 of them, and they worked for Charlemagne rather than King Arthur. The name itself derives from the Palatini, the guards of the Roman Emperor's personal palace of Palatine hill. Like the Knights of the Round Table, the Paladins were famous for their feats of heroism (especially in battle against Moorish invaders from Spain) and their piety.

As to the Paladin in fantasy, it came through D&D (like so many standard fantasy tropes), through Poul Anderson's novel Three Hearts and Three Lions, about a World War II resistance fighter, Holger Carlsen, who travels to a parallel, high-fantasy universe where the legends of the Twelve Peers are real, and turns out to be that universe's version of Ogier the Dane, one of the Paladins. Other important D&Disms that come from that novel include trolls that regenerate their wounds and Law and Chaos as forces that exist in opposition like Good and Evil.