Iar Chonnachta (longer form – Iarthar Chonnachta) (anglicised spelling- Iar Connaught) (meaning west of the Connachta, or western Connacht), was a region covering all of County Galway west of the river Corrib and Lough Corrib; Maigh Seola; and part of the barony of Ross in County Mayo.
The area of Co. Galway, lying between Kilkieran Bay to the west and Lough Corrib to the east, is sometimes described as Iar Connaught on some maps and books, however this is incorrect, as this area was the territory of Dealbhna Thíre Dhá Locha which only ever formed a part of Iar Chonnachta. Roderick O'Flaherty was the last de jure Lord of Iar Connacht. He wrote the history of Iar Connacht (published in 1793) and was the last recognised chief of the O'Flaherty clan.
Maigh Seola the part of County Galway east of Lough Corrib, stretching from Tuam to Athenry to Maree was included in Iar Chonnachta before the 13th century. After its leading family, the O'Flahertys, were expelled west of Loch Corrib and the Galway (now Corrib) River during the English invasion of Connacht, Maigh Seola was no longer considered to be in Iar Chonnachta.
Since the middle of the 19th century most of Iar Chonnachta has been generally called Connemara largely due to the emerging tourist industry of that time.
The territory of Dealbhna Thíre Dhá Locha / Delbhna Tir Dha Locha covered the eastern half of Iar Chonnachta.
Connemara / Conmhaicne Mara (Conmaicne Mara) covered the western portion of the territory. Joyce Country (the Barony of Ross) covered the north-eastern portion of Iar Chonnachta.
The native rulers of Joyce Country were the Partraighe an tSléibhe whose territory also covered the south of the barony of Carra in County Mayo.
Maigh Seola the plain lying on eastern side of Lough Corrib was also considered to be part of Iar Chonnachta up until the 13th century when the native rulers of Maigh Seola – the O Flahertys / Uí Fhlaithbheartaigh – were ousted from Maigh Seola during the Norman invasion of Connacht in that century.
As they were the most powerful clan in this part of Connacht it seems that the O Flahertys and the earlier kings of Maigh Seola held some sway over all of Iar Chonnacht even before been were forced west of Loch Coirib. The O Flahertys are believed to have had control over Dealbhne Thíre Dhá Locha before leaving Maigh Seola. When the O Flahertys fled west of Lough Corrib, they established complete rule over the native clans there. The O Flahertys remained as lords of Iar Chonnachta until they lost their lands in the upheavals of the mid 17th century.
It is uncertain if the Aran Islands formed part of the territory.
Kings of Maigh Seóla (later Uí Briúin Seóla)
- Donn mac Cumasgach, died 752
- Maelan mac Cathmogha, died 848
- Murchadh mac Maenach, died 891
- Urchadh mac Murchadh, died 943
- Donnchadh mac Urchadh, died 959
- Brian mac Maelruanaidh, died 959
- Muireadhach ua Flaithbheartach, died 1034
- Murchadh an Chapail Ua Flaithbheartaigh, died 1036
- Cathal mac Ruaidhri, died 1043
- Amhalgaidh mac Cathal, blinded 1051 (died 1075)
Kings of Iar Connacht
- Cathal mac Tigernán, died 1059
- Rúaidhri Ua Flaithbheartaigh, died 1061
- Aedh Ua Flaithbheartaigh, died 1079
- Mac meic Aedh Ua Flaithbheartaigh, died 1091
- Flaithbertaigh Ua Flaithbertaigh, died 1098
- Brian Ua Flaithbertaigh, died 1117
- Muireadhach Ua Flaithbheartaigh, died 1121
- Conchobhar Ua Flaithbheartaigh, died 1132
- Ruaidhri Ua Flaithbheartaigh, died 1145
- Áedh Ua Flaithbheartaigh, died 1178
- Conchubhar Ua Flaithbheartaigh, died 1186
- Ruadhri Ua Flaithbertaigh, alive 1197
- Murtough Ua Flaithbertaigh, died 1204
- Rudhraighe Ó Flaithbheartaigh, fl. 1214 (Brian, the son of Rory O'Flaherty, the son of the Lord of West Connaught, died.)
- Áedh Mór Ó Flaithbheartaigh, died 1236
- Morogh Ó Flaithbheartaigh, fl. 1244
- Ruaidhri Ó Flaithbheartaigh, fl. 1256–1273
Taoiseach of Iar Connacht
- Brian Ó Flaithbheartaigh, died 1377.
- Áedh Ó Flaithbheartaigh, c. 1377–1407; built the church at Annaghdown
- Domnell mac Áedh Ó Flaithbheartaigh – 1410. Donnell, the son of Hugh O'Flaherty, Lord of West Connaught, was slain by the sons of Brian O'Flaherty, at a meeting of his own people.
- 1417. Rory, the son of Murrough O'Flaherty; Rory, the son of Dermot Duv O'Flaherty, and sixteen others of the O'Flahertys, were drowned in the bay of Umallia.
- Murchad mac Brian Ó Flaithbheartaigh – 1419. Murchad son of Brian O Flaithbertaig, king of West Connacht, died this year.
- 1422. Donnell Finn O'Flaherty was slain by the sons of Donnell O'Flaherty.
- 1439. Owen O'Flaherty was treacherously slain in his own bed at night, by a farmer of his own people.
- Gilla Dubh Ó Flaithbheartaigh – 1442. O'Flaherty, i.e. Gilladuv, the son of Brian, Lord of West Connaught died.
- 1503. Teige Boirneach, Murrough and Mahon, two sons of Mahon O'Brien; Conor, the son of Brian, son of Murtough, son of Brian Roe; the son of O'Loughlin, i.e. Conor. the son of Rory, son of Ana; and Murtough, the son of Turlough, son of Murrough, son of Teige; went with Owen, the son of O'Flaherty, into West Connaught, with numerous forces, the same Owen having drawn them thither against his kinsmen (Rory Oge and Donnell of the Boat, two sons of O'Flaherty), who were encamped at Cael-shaile-ruadh, awaiting them. The O'Briens and Owen attacked the camp, and carried away preys and spoils. The sons of O'Flaherty and the people of the country followed in pursuit of them, so that a battle was fought between them, in which the sons of Mahon O'Brien and Owen O'Flaherty were slain by the O'Flahertys.
- Áodh Ó Flaithbheartaigh, fl. 1538
- M1542.15. The crew of a long ship came from West Connaught to Tirconnell, to plunder and prey. The place which they put in at was Reachrainn-Muintire-Birn, in Tir-Boghaine. When Turlough, the son of Mac Sweeny of Tir-Boghaine, received intelligence of this, he made an attack upon them, so that none of them escaped to tell the tale of what had happened, except their chief and captain, namely, the son of O'Flaherty, to whom Mac Sweeny granted pardon and protection; and he sent him home safe, outside his protection, to Conmaicne-mara.
- Clann Fhergail
- Uí Fiachrach Aidhne
- Clann Taidg
- Conmhaícne Mara
- Delbhna Tir Dha Locha
- Muintir Murchada
- Uí Maine
- Síol Anmchadha
- Maigh Seola
- Medieval Ireland: Territorial, Political and Economic Divisions, Paul MacCotter, Four Courts Press, 2008, pp. 133–134. ISBN 978-1-84682-098-4