Lilly, Lilley, and Lillie in Ireland

In Ireland, the name O'Laechaille was anglicized as Leech and
Lilly. The name Mac Ailghile (Mac Ghailghile), pronounced like
the words ale and gile, was a sept related to the MacGuires of
County Fermanaugh, Ulster Province, Ireland. Mac Ailghile was
anglicized as MacAlilly which became Lilly, Lilley, and Lillie.
The central Ulster Lilleys were MacAlillys.
The McGuire name originated with the ancient name of Guire,
founded by Colla da Crioch, son of Eocha Dubhlein, son of Carbre
Lifleachair, King of Ireland, A.D. 264. Eocha Dubhlein of
Doivlen founded the Hy Many Tribe.
In old Ireland, names were related to tribes, more than to
blood lines.