This distinguished Irish surname is an Anglicized form of the old Gaelic Mac Maghnuis or Mac Manus. The Gaelic prefix "mac" meaning "son of", plus the personal name Manus, ultimately from the Latin "magnus" meaning "great", and popular with the Normans who had adopted it in honour of the Emperor Charlemange (742 - 814); Latin name Carolus Magnus i.e. Charles the Great. Magnus was also a popular Scandinavian personal name, and Magnus the Good, King of Norway, (deceased 1047), was named after the Emperor Charlemange. It was the Norsemen who introduced this personal name to Ireland where it later took the form Manus. Two main septs of M(a)cManus exist in Ireland. The first is descended from one Maghnus (deceased 1181), son of Turlough O' Connor, High King of Ireland, (1119 - 1156). They belonged to Kilronan in the Connacht county of Roscommon. The second family, a branch of the Maguires, descend from Magnus, son of Donn Maguire, Chief of Fermanagh, who died in 1302. This family lived on the shores of Lough Erne, COunty Fermanagh, and Belle Isle in that lake was formerly called Ballymacmanus in their honour. The first recorded spelling of the family name is shown to be that of Hugh Mcmanus, (marriage to Mary Gawin), which was dated 1662, Derry Cathedral, Templemore, Derry, during the reign of King Charles 11, of England, 1660 - 1685. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.