Which High King of Ireland conquered Munster, Leinster and Connacht in 976 AD?
Toirdelbach Ua Briain Toirdelbach Ua Briain Toirdhealbhach Ua Briain (old spelling: Toirdelbach Ua Briain), anglicised "Turlough O'Brien" (100914 July 1086), was King of Munster and effectively High King of Ireland. A grandson of Brian Bóruma, Toirdelbach was the son of Tadc mac Briain who was killed in 1023 by his half-brother Donnchad mac Briain. For the first forty years of his life nothing is known of Toirdelbach. It was not until the 1050s that he found allies in Connacht and in Leinster, particularly the powerful King of Leinster Diarmait mac Maíl na mBó, who would aid his claims to be ruler of Munster.
Flag and coat of arms of Connacht assumed that the arms of the "Schottenkloster" were similarly conceded to the other royal benefactors noted in the necrology, then an explanation of the origins of the arms of the province of Connacht begins to emerge because the final entry in the necrology refers to Ruaidhrí Ó Conchobhair, King of Connacht and last High King of Ireland. The flag of Connacht is usually displayed alongside the flags of Leinster, Munster and Ulster, or as part of the combined flag of the Provinces of Ireland. The flag is the official flag of the Connacht Gaelic Athletic Association and the Connacht rugby