Connacht, formerly also spelled Connaught (/ˈkɒnɔːt, ˈkɒnə(x)t/, Irish: Connachta [ˈkʊn̪ˠəxt̪ˠə] or Cúige Chonnacht [ˌkuːɟə ˈxʊn̪ˠəxt̪ˠ]), is the smallest and least populous of the four provinces of Ireland, situated in the west of Ireland. Until the ninth century it consisted of several independent major Gaelic kingdoms (Uí Fiachrach, Uí Briúin, Uí Maine, Conmhaícne, and Delbhna).
Between the reigns of Conchobar mac Taidg Mór (died 882) and his descendant, Aedh mac Ruaidri Ó Conchobair (reigned 1228–33), it became a kingdom under the rule of the Uí Briúin Aí dynasty, whose ruling sept adopted the surname Ua Conchobair. At its greatest extent, it incorporated the often independent Kingdom of Breifne, as well as vassalage from the lordships of western Mide and west Leinster. Two of its greatest kings, Tairrdelbach Ua Conchobair (1088–1156) and his son Ruaidri Ua Conchobair (c. 1115–1198) greatly expanded the kingdom's dominance, so much so that both became High King of Ireland.