McManus — Keepers of the Annals

McManus anglicises Mac Maghnusa, ‘son of Maghnus’ — the Gaelic form of Magnus, a name the Norse brought to Ireland, itself from the Latin for ‘great’. Two unrelated septs carried it: one in Roscommon, from Maghnus (d. 1181), son of the High King Turlough Mór O’Conor, and one on the shores of Lough Erne in Fermanagh, a branch of the Maguires descended from Magnus, son of Donn Maguire.

It was a Fermanagh McManus, Cathal Óg Mac Maghnusa (1439–1498), who was the principal compiler of the Annals of Ulster — a family that kept Ireland’s own record, not just its own name.

Irish form: Mac Maghnusa