Knight Rank

'Knight' is a common title in the world, and means simply a warrior who owns land (or their progeny). Sons and daughters of knights who do not inherit property are themselves knights, though typically any family they have no longer holds this title. The exception is when said children have weapons and armor and have been trained to use them; though knights can be any kind of warrior, they are invariably martial, and in most societies occupy a specific class. Even in the Republic, knights are found among the officer corps, as most have been trained from a young age to be warriors.
The term is different in different languages, but noble or semi-noble warriors are common enough. Membership criteria also varies; some places require oaths, others certain requirements being met, and still others any man or woman with a sword who knows how to use it can claim the title.