The Sheehan Surname: Peaceful Warriors originating from the Dál gCais in Munster Ireland The Sheehan name, from Gaelic Ó Siodhacháin meaning "descendant of the peaceful one," carries a rich history tied to Ireland's Munster province and the mighty Dál gCais tribe. Featured in genealogy radio discussions from Kilkee, it ranks among Ireland's top surnames, with deep roots in Limerick, Clare, Cork, and Kerry. This blog expands on transcripts, documents, and historical sources to trace Sheehans from ancient clans to a global diaspora. Etymology and Early Roots Sheehan derives from Ó Siodhacháin, a patronymic where "Ó" means "descendant of," linked to "siodhach" (peaceful) or "siodach" (gentle). Celtic scholars question a purely peaceful origin, emphasising its Dál gCais sept status in Thomond (North Munster), extending across modern Limerick, Clare, Tipperary, Kerry, and Offaly. The clan seated in Lower Connello barony, south L...