From "A New History of Ireland" ISBN 0-19-821745-5, p137:
King of Munster from 1168-1194.

He built and endowed the Abbey of Corcomroe in Clare in 1194.12

The History and Topography of the County of Clare by James Frost Part I. Topography of Thomond Chapter 3. Burren, or Corcomroe East
This parish derives its name from the Abbey of Corcomroe, sometimes also called the Abbey of Burren, founded for Cistercian monks in 1194 by Donald O’Brien, King of Thomond, or, as others say, by Donogh Cairbreac, his son, in 1200. It was called “the abbey of the fruitful rock,” and was a daughter of that of Suir. Later it was made subject to the Abbey of Furness, in Lancashire, and it had a cell at Kilshanny near Ennistymon, to which it sent monks as occasion demanded. It was dedicated to the Blessed Virgin Mary.

He founded St Mary's Cathedral in LImerick 1172. In 1175 he blinded Dermod, son of Teige O'Brien, and Mahon, son of Turlogh, his kinsmen, which act caused the death of Dermod soon after, at Castleconnell. In 1176, Donal expelled theAnglo-Normans from the City of Limerick, putting most of Henry II's garrison to the sword. In 1192 he drove the English out of Upper Ormond, Ara and Coonagh, where they established themselves; and stripping them of the booty they took from the native chieftains.9

Dónal Mór O'Briain (1168 - 1194)
Dónal Mór was absolute king of Thomond when the Normans came and he was able to keep them at bay from his kingdom, which included Clare, Limerick, North Tipperary and part of Offaly, up to the time of his death in 1194. Dónal Mór had strong ties with some of the leading Norman families and he was not opposed to the English except where they threatened his kingdom. Both he and Strongbow married a daughter of Dermot McMurrough, King of Leinster; while Dónal Mór's daughter married Richard de Burgh a powerful Norman baron in Limerick and Galway. Dónal Mór even assisted Strongbow and the Normans in some of the campaigns against the Kings of Ossory, Desmond and Connaught (traditional enemies of the Uí Briain).
When Henry II visited Ireland in 1171 Dónal Mór submitted to him at Cashel and paid homage, thus acknowledging Henry's lordship of Ireland. In agreeing to pay tribute to Henry II, Dónal Mór became in effect, a tenant-in-chief of the English king. Shortly after this submission Henry attempted to deprive Dónal Mór of his kingdom by granting all of Thomond to one of his knights, Philip de Braose, in 1173. When Philip and other Normans, including Strongbow, tried to enforce this claim by invading Thomond, they were repulsed by Dónal Mór's army at the battle of Thurles in 1174, in which over 700 were slain. In 1175 Raymond le Gros, another leading Norman adventurer, captured Dónal Mór's capital of Limerick by bringing a fleet up the Shannon. A year later, however, Dónal Mór re-gained the city and burnt it, rather than suffer it to be held by foreigners. From 1176 up to his death in 1194 the Normans made no further inroads into Thomond.