The story
* As an English surname, from the Middle English personal name Elis, an Old French form of Elias. Compare Elijah, Lias, Ely. Also sometimes from the Elice, a pet form of Elizabeth. * As a Welsh surname, shortened from the personal name Elisse, Elisedd, from the archaic elus (“benevolent, kind”).
Etymology from Wiktionary, CC BY-SA 4.0.