Recorded in the spellings of Fenlin, Fenelon, Fenlon, Finl;and and possibly others, this is an ancient Irish and sometimes a French surname. It derives from the pre 10th century Gaelic O'Fionnallain, which translates literally as the descendant of the son of the fair one, and is probably a reference to the first chieftain, who may have been a Viking. The Norsemen conquered much of Ireland in the 8th century a.d., and Dublin was their capital. The name would seem to be a reference to one who was fair haired andf fair skin, whilst the original natives like the Welsh and Olde English were more swarthy and dark complexioned. Certainly the vast majority of Irish surnames are nicknames from the original chhiefs, and this name is no exception. It is not clear when the O' prefix was lost but it was probably in the 17th century when name spellings took on a more English form. The clan originated in County Westmeath, and were also "fused" with French Fenelons, who were Huguenots who entered both England and Ireland as refugees in the 18th century.