The Knights are one of the major factions in the game, the other being the Corsairs. They originated as a group of rebels, during the time that the Corsairs controlled Ar'krad. They believe in fighting for freedom and justice.
There is a reason the Humans are the first race on the list of Knights Races. King Arryhowl founded the Knights, out of pure hatred for Blood Orcs. They started as a secret group, but eventually the rage against being controlled by Blood Orcs and the other races of the Corsairs drove the whole species into this group, thus making Arryhowl king. They started by a few massacres here and there, but eventually found other races to join them.
The Coming of the Shadow ElvesEdit
The first race, that joined, the Shadow Elves begged and pleaded to join the group of rebellious Humans that made up the Knights. They begged for this because they had been long forgotten, and the Shadow Elves overwhelming pride made them want to become one of the most known races of Ar'krad, as they had been before the uprising of the Blood Orcs. The Humans never completely understood the motives of the Shadow Elves, but they welcomed their new ally with open arms.