This is an Irish surname of great antiquity and also great confusion. Recorded in a number of spellings including MacMenamin, McMenamin, MacManamon, McManamon, McMennuam, McMennum, and cross integrated with such English and Scottish surnames such as Merriman, Marmion and even the Irish O'Merry, much remains to be dscovered as to its true origins, even its translation being uncertain. There is a claim that it derives from the Gaelic "Mag giolla Mheidre", meaning "the son of the merryman", but this is disputed as being a translation of the English surname Merryman, also widely recorded and overlapping in Ireland, and therefore not a logical explanation. The surname is popular in Counties Donegal and West Tyrone, and is said to be one of the first ever recorded in Ireland. In the Gaelic period before 1170 a.d. when Ireland was invaded by an Anglo-Welsh army, the clan were the chiefs of the barony of Iffa and Offa West. The surnames Marmion and Merriman are claimed to be the spelling forms in the Dublin area, however this has to be treated with considerable doubt as both these names are to be found in England. The first known and proven recordings are of two brothers Teag and Maol MacMenamin. They were given as being nephews of the great chief O'Neill, and it is claimed that they both died in the year 1303, probably as a result of battle injuries, although even this is not certain.