Callahan History, Family Crest & Coats of Arms

Before Irish names were translated into English, Callahan had a Gaelic form of Ó Ceallachain, possibly from “ceallach”, which means “strife”. The family is descended from Ceallachan (Callaghan), the 10th century King of Munster from whom their surname is derived, and as such, the name Callahan is a patronymic name. 1

Early Origins of the Callahan family

The surname Callahan was first found in Munster. The earliest mention of the name Callahan placed them in the barony of Kinlea, in County Cork, yet the family lost most of their original lands in the barony of Kinelea during the Anglo-Norman Conquest under Strongbow. They relocated to an area near Mallow, in the north of the county, and remained there until forced off their lands once again during the Cromwellian Invasion of the 17th century.

The head family migrated to the east of County Clare and flourished, giving their name to the village of Callaghan’s Mills. The resumption of the often-discarded prefix “O” has been widespread during the late twentieth century, but in the early twentieth century, Callaghans greatly outnumbered O’Callaghans, but such is no longer the case. The O’Callaghans are one of the few Irish families to still have a chief, certified by the Genealogical Office. 2