Efrog (or Evrawc or Evraỽc) is the father of Peredur Longspear in medieval Welsh tradition. This name is found nowhere else as a personal name, but is the common Welsh name for the city of York, in Latin, Eburācum. According to Rachel Bromwich (2206, p. 478), Pokorny in Beiträge zur Nemenforschung I (1950) suggests that the name P(e)redur (m)ab Evrawc might derive from the Latin title Pr(a)etor ab Eburāco (‘a magistrate of York’) with the preposition ab being interpreted as the Welsh word for ‘son’.