Lord of Connaught was a title used by several Norman barons in Ireland. Granted to William de Burgh, the lordship was claimed by his son, Richard Mor de Burgh, and his descendants.
During the Norman invasion of Ireland, William de Burgh (d.1206) was apparently granted Connacht, but never took possession of it. It remained in the hands of native kings until 1224, when his son, Richard Mor de Burgh, claimed it on the basis of his father's grant. Richard's uncle Hubert de Burgh was then Justiciar of Ireland and upheld the claim in 1227. Richard called upon the feudal levies of Ireland and conquered Connacht (1235), assuming the title Lord of Connaught.
Richard's son Walter de Burgh, 1st Earl of Ulster, his son Richard Óg de Burgh, 2nd Earl of Ulster, and Richard Óg's grandson William Donn de Burgh, 3rd Earl of Ulster all seem to have used the title but, on the death of the latter in 1333, civil war broke out over control of the de Burgh lands.
Connacht was divided between Sir Ulick Burke (1st Mac William Uachtar (Upper Mac William) or Clanricarde, Galway) and Edmond Albanach de Burgh (1st Mac William Íochtar or Lower Mac William, Mayo)[1] and the title fell out of use. It was not recognized in the Peerage of Ireland, and the heirs-general of William Donn, who retained the title Earl of Ulster, did not continue to use it.