Muireadhach mac Samhradháin, was the first person to bear the surname McGovern and was chief of the McGovern Clan and Baron or Lord of Tullyhaw barony, County Cavan from c.1115 - 1148.
[1] Poem 2, stanza 8, by Giolla Pádraig mac Naimhin, written c.1290-1298, in the Book of Magauran describes Muireadhach as stern-faced Muireadhach who sent his warriors patrolling each ford.
[2][3] Muireadhach was probably born in Moneensauran townland, Glangevlin, County Cavan, where his father Samhradhán lived.
There are three medieval ringforts in the townland, one of which was probably his residence.
His son was Giolla na Naomh mac Muireadhach Mág Samhradháin, head of the lineage from c.1160-1200