Muirchertach Ua Briain
Appearance
![](http://chped.net/https/upload.wikimedia.org/wikipedia/commons/thumb/4/44/Muirchertach_Ua_Briain.jpg/220px-Muirchertach_Ua_Briain.jpg)
Muircheartach Ua Briain (anglicised as Murtaugh O'Brien; c. 1050 – c. 10 March 1119), son of Toirdelbach Ua Briain and great-grandson of Brian Boru, was King of Munster and later self-declared High King of Ireland.