O'Flaherty ( , ; ; ) is an Irish Gaelic clan based most prominently in what is today County Galway. The clan name originated in the 10th century as a derivative of its founder Flaithbheartach mac Eimhin. They descend in the paternal line from the Connachta's Uí Briúin Seóla. They were originally kings of Maigh Seóla and Muintir Murchada and as members of the Uí Briúin were kinsmen of the Ó Conchubhair and Mac Diarmada amongst others. After their king Cathal mac Tigernán lost out to Áed in Gai Bernaig in the 11th century, the family were pushed further west to Iar Connacht, a territory associated with Connemara today. They continued to rule this land until the 16th century. The name has been alternatively rendered into English in various forms, such as Flaherty, Faherty, Laverty, Flaverty, Lahiff, and Flahive. Naming conventions Overview This Gaelic-Irish surname is written as "Ua Flaithbertach" (nominative) or "Ua Flaithbertaig" (genitive) in Old Irish and Middle Irish texts. In Modern Irish the surname is now generally spelt as Ó Flatharta. The surname is commonly translated as "bright ruler" or more correctly "bright prince", flaith originally meaning prince in Irish. "O" or Ó comes from Ua, designating "grandson" or "descendant" of a (major) clan member. The prefix is often anglicised to O', using an apostrophe instead of the Irish síneadh fada: "'". Maigh Seóla was the earliest O'Flaherty domain, to the east of Lough Corrib in the kingdom of Connacht, the westernmost province of the Island of Ireland (Irish: Éire). The Ó Flaithbertaighs are a branch of the Muintir Murchada dynasty, named after Murchadh mac Maenach (died 891), King of the Uí Briúin Seóla. Murchadh is one of the earliest attested kings of his region. The leading family of this dynasty would take the surname Ó Flaithbheartaigh (O'Flaherty) from the 11th century onwards. Kings of Magh Seóla The Uí Briúin Seóla was one of the major branches of the powerful Uí Briúin dynasty, which had become the dominant force in Connacht by the 8th century. The genealogies list two sons of Murchadh mac Maenach: Urchadh and Urumhain. Urchadh mac Murchadh, King of Maigh Seóla (also listed as king of Iarthair Connacht, died 945, in the 14th century Book of Ballymote) was father of Bé Binn inion Urchadh, Princess of the Uí Briúin Seóla and Queen of Thomond (fl. early 10th century). Bé Binn married Cennétig mac Lorcáin