Doilfín
DOILFÍN—VIII—Dolfine, Dolfin, Dolphin; 'son of Dolfin,' a common personal name in England even before the Norman conquest. It occurs in Domesday Book as the name of a landholder in the time of Edward the Confessor, and about 1085 was borne by an Earl of Cumberland. In Ireland, the Dolphins settled in Clanrikard, where in the 16th century they formed a distinct clan after the Irish fashion with a chief of the name.
Alphabetical Index to Irish Surnames