Who were called knights and how did they become?

Knights were people from the nobility who took the oath of allegiance to their overlord and began service, usually military, although there were diplomatic and other. Knights took an oath of allegiance and received initiation and a sword from the hands of the overlord.

There were also knights of the militant orders of the Catholic Church. Their suzerain was not the duke or the king, but the Pope himself.

Knights began their service as squires and pages, and only after serving for some time were ordained to knighthood. Such initiates were already becoming full-fledged knights.