A castle warrior or castle serf (Hungarian: várjobbágy, Latin: iobagio castri)[1][2] was a landholder obliged to provide military services to the ispán or head of a royal castle district in the medieval Kingdom of Hungary. Castle warriors "formed a privileged, elite class that ruled over the mass of castle folk"[3] (Pál Engel) from the establishment of the kingdom around 1000 AD. Due to the disintegration of the system of castle districts, many castle warriors became serfs working on the lands of private landholders in the 13th and 14th centuries; however, some of them were granted a full or "conditional noble" status.