Connacht is the smallest and most westerly of the four provinces. It includes counties Galway, Mayo, Sligo, Roscommon and Leitrim.
The name of the province derives from the Connachta, the large tribal grouping which dominated the west and north of the island in the first few centuries A.D. They claimed descent from the mythical Conn, brother of Eogan, the ancestor of the rulers of Munster, the Eoghanachta. By far the most important of the Connachta were the Uí Néill, who ruled much of the northern and eastern parts of Ireland. The Uí Brion and the Uí Fiachra , offshoots of the southern Uí Néill based at Tara in Co. Meath were dynastic kings of Connacht from the fourth century down to the arrival of the Normans in the late twelfth century, when the entire territory was granted to the de Burgos. These were eventually completely assimilated into Gaelic culture, becoming the Mayo and Clanricard Burkes, and, in true Irish fashion, producing many offshoot families, among them Gibbons, Jennings and Philbin, all surnames still commonly found in Connacht.
Because of their remoteness and the relative poverty of the land, the counties of Connacht, together with Co. Clare, were excluded from the confiscations following the wars of the seventeenth century, and became a refuge of sorts for those dispossessed elsewhere. By the nineteenth century the region was densely populated and desperately poor, with the result that its people suffered disproportionately in the Famine and the mass emigration that followed.