Brian Ua Briain II "the Lecher" of Mumu (1048-), also known as King Brian O'Brian of Munster was King of Mumu from 1069, succeeding Murchad of Mumu. Brian was a descendant of King Brian Boruma, the hero of the Battle of Clontarf, and he ruled over Munster during the late 11th century, fighting to maintain Munster's independence from the new Kingdom of Eire.