Domhnall Caomhánach

Domhnall Caomhánach (Domhnall mac Murchada or Domhnall Caomhánach mac Murchada, anglicized as Donal Kavanagh) is the ancestor of the Caomhánach line of the Uí Ceinnselaig dynasty and was King of Leinster from 1171 to 1175. Domhnall was the eldest son of the 12th century King of Leinster, Diarmait Mac Murchada in Ireland.
Domhnall was fostered for his training and education at the monastery of St. Caomhan at Kilcavan in the Barony of Gorey, County Wexford. In an effort to distinguish himself from his other brothers, Domhnall assumed the name Caomhánach (an adjective of the name Caomhan, meaning "of Caomhan"). Contrary to usual Irish practice, the name was adopted by his descendants as an inherited surname.

After the death of his father Diarmait Mac Murchada in 1171, Domhnall was proclaimed King of Leinster by the Irish clann chiefs. Domhnall's legitimacy to the title was widely disputed by the Cambro-Norman invaders who viewed that their leader, Strongbow (Richard de Clare, the 2nd Earl of Pembroke), was the legitimate successor due to his marriage to Domhnall's sister Aoife and that Domhnall's claim was "illegitimate" under Norman law. However under Irish Brehon Law, Strongbow had absolutely no basis for his claim.

In 1175, it is recorded in the Annals of the Kingdom of Ireland that Domhnall was slain by O'Foirtchern and O'Nolan during the Battle of Naas. He is buried near his father Diarmait Mac Murchada in the Cathedral graveyard of Ferns village. After his death, Domhnall was succeeded as King by his grandson Muirchertach, the son of Domhnall Oge Caomhánach.