McManus aka McMaghnuis

McManus is an Irish surname. It is derived from the Irish Gaelic “Mac Mághnais”, in modern Irish “McMaghnuis” which means “Son of Magnus”.

Its earlier origin is from the Latin “magnus”, meaning “great”. The Normans used it to honour Charlemange (742–814), as Carolus Magnus (Charles the Great).

Variant spellings of the name include MacManus, Manus and MacManners. The English form, Moyne, is also found in Ulster. In Scotland it is a sept of Clan Colquhoun.

There are two principal septs of the name in Ireland:

Maghnus

One descends from Maghnus (d. 1181), son of Turlough Mór O’Conor, High King of Ireland (1119–1156 this branch belonged to Kilronan in the county of Roscommon in the province of Connacht.

Maguires

The second sept was a branch of the Maguires, who descend from Magnus, son of Donn Maguire (Donn Mag Uidhir), Chief of the Kingdom of Fermanagh (d. 1302). This family lived on the shores of Lough Erne, in what is now County Fermanagh.