Maelruanaidh Mor mac Tadg, first King of Moylurg, and ancestor to all subsequent Kings of Moylurg. He is usually assumed to have lived in or about the year 956.

Maelruanaidh was a son of Tadg mac Cathal (King of Connacht 925-956) and brother to Conchobar mac Tadg, who succeded as king in 967. Indeed he could claim no less than ten ancestors as Kings of Connacht since the sixth centuary. Maelruanaidh is said to have made a deal of some nature where, in return for abandoing any claim to the provincial kingship, he would be given Moylurg. His dynasty were known as the Clan Mulrooney, and later still took the surname of MacDermot.