The kings of Thomond (Irish: Rí Tuamhain) ruled from the establishment of Thomond during the High Middle Ages, until the Early modern period. Thomond represented the legacy of Brian Bóruma and the High Kings of Ireland of his line who could not hold onto all of Munster, so had to partition the realm between themselves and Desmond, ruled by their rivals the Eóganachta. The Kings of Thomond were drawn from the leading kindred of the Dál gCais known as the Ó Briain. For centuries they fought off challenges from the Normans, including the de Clare family and internal conflict between factions. Eventually Murchadh Carrach Ó Briain decided to surrender and regrant his realm to the Kingdom of Ireland in 1543 and accepted the titles Baron Inchiquin and Earl of Thomond. These titles were recently held by Conor Myles John O'Brien (d.2023)