Donnchad mac Domnaill Remair

In 1071, the Annals of the Four Masters reveal conflict amongst the Uí Cheinnselaig, as this source states that Donnchad fought his first cousin once removed, Domnall mac Murchada meic Diarmata.

[2] The following year, in the immediate aftermath of the death of Donnchad's uncle, Diarmait mac Máel na mBó, King of Leinster, Toirdelbach Ua Briain, King of Munster overran Leinster, and attacked Dublin.

Toirdelbach then appointed Domnall to the kinship of Dublin, and allowed Leinster to be ruled by Donnchad.

In 1087, Muirchertach, now King of Munster, made moves to regain Uí Briain control of Dublin, and won a battle at Ráith Etair, north of the River Liffey.

[7] Muirchertach himself was unable to hold the town for long, losing it to Gofraid Crobán, King of the Isles about two years later.