Connacht today is five counties: Galway, Leitrim, Mayo, Roscommon, and Sligo. Galway is the only city. The province is roughly bounded by the River Shannon on the east and the Atlantic Ocean on the west. The highest point is Mweelrea, 814 metres, in County Mayo. The largest lake is Lough Corrib. The largest island is Achill. The west coast - Connemara, Erris - is ruggedly inhospitable: thin soils, exposed rock, weather that comes in off the Atlantic with nothing to slow it down. The main mountainous areas are the Twelve Bens, the Maumturks, Mweelrea, Croagh Patrick, the Nephin Beg range, the Ox Mountains, and the Dartry Mountains. Killary Harbour at the foot of Mweelrea is one of Ireland's three genuine fjords. The Aran Islands, with their prehistoric stone forts at Dun Aonghasa, have been drawing visitors since the 19th century.

Until the 9th century the territory now called Connacht was a region rather than a kingdom, divided among several major Gaelic peoples - the Ui Fiachrach, Ui Briuin, Ui Maine, Conmhaicne, and Delbhna. Between Conchobar mac Taidg Mor in the 9th century and Aedh O Conchobair in the 13th, the Ui Briuin Ai dynasty consolidated power. Their ruling sept took the surname Ua Conchobair. Two of their kings - Tairrdelbach Ua Conchobair (1088-1156) and his son Ruaidri Ua Conchobair - became High Kings of Ireland. Ruaidri, crowned at Dublin in 1166, was the first and last native ruler recognised by the Gaelic Irish as full King of Ireland. His expulsion of Dermot MacMurrough the same year led directly to the Norman invasion of 1169. Ruaidri died at Cong in 1198. The Kingdom of Connacht collapsed in the 1230s in a civil war that opened the door to widespread Norman settlement under Richard Mor de Burgh.

Connacht's population in 1841 was 1,418,859. By 1851, after the worst years of the Great Famine, it had fallen to 1,010,031 - a drop of more than 400,000 in a decade, through death and through emigration. Mayo and Roscommon were among the worst-hit counties in Ireland. The decline did not stop in 1851. It continued for more than a century. By the late 20th century Connacht's population had fallen to under 400,000, less than a third of what it had been before the potato failed. The 2022 census recorded just under 590,000 - a slow recovery that has still not brought the province back to its pre-Famine size. The empty landscapes of west Mayo and Connemara, the abandoned cottages on hillsides, the silent stone-walled fields, are not romantic. They are the negative space left by people who could no longer live there.

Anglicisation worked less thoroughly in the west of Ireland than in the east, and Connacht today has the highest concentration of Irish speakers among the four provinces. Around 39.8 percent of people in Connacht consider themselves Irish speakers - more than 202,000 people. The largest Gaeltacht (Irish-speaking) areas in Ireland are in counties Galway and Mayo, particularly in Connemara and on the islands. The language survives in these places not as a heritage performance but as the working language of homes, schools, and shops. The radio station Raidio na Gaeltachta and the television station TG4 are both based in Connemara. The choice the conqueror once offered Connacht - hell or here - left the province with a quieter weapon than expected: it kept its language.

Connacht was the site of two of the bloodiest battles in Irish history. The Second Battle of Athenry in 1316 and the Battle of Knockdoe in 1504 each produced casualties measured in the thousands - very high for medieval Irish warfare. A third, the Battle of Aughrim on 12 July 1691, killed an estimated 10,000 and effectively ended the Williamite War in Ireland. In 1798 General Jean Humbert landed French troops at Killala on the Mayo coast to support the United Irishmen rising; the resulting brief Republic of Connacht was crushed at the Battle of Ballinamuck. Throughout the 19th and 20th centuries the province continued to lose people - to the Famine, to emigration to America and Britain, to internal migration toward Dublin. And yet Connacht Rugby plays in Galway. The Connacht Tribune publishes in Galway. The province has no official function in modern Irish local government, but it remains, in the way old provinces do, a fact of identity. Anyone from any of the five counties knows it.