The story
From the Middle English patronymic surname Elpheg [1297], Alfegh [1318], which originated in Kent or Sussex, from the given name Elfegh, Alfeg, etc. (Modern English Alphege), altered under Anglo-Norman influence from the earlier Ælfec, Ælfech, Ælfhag, Alfeg, Elfech, Elfeg (all recorded in the Domesday Book of 1086), then a popular male given name bestowed in honour of the martyr St Alphege (c. 953–1012), Archbishop of Canterbury 1006–1012, from the Old English given name Ælfhēah, from ælf (“elf”) + hēah (“high, tall, exalted”). Probably cognate with the Norman Elphège.
Etymology from Wiktionary, CC BY-SA 4.0.