This notable Irish surname is an Anglicized form of the Old Gaelic "MacSuibhne", son of Suibhne, a male given name from "suibneus, suaimhneas", easy-going, pleasant. Traditionally, Irish family names are taken from the heads of tribes, revered elders, or some illustrious warrior, and are usually prefixed by "Mac", denoting "son of", or "O", grandson, male descendant of. Suibhne, from whom this great family claims descent, was lord of Knapdale in Argyllshire, Scotland, at the end of the 12th Century, and his descendants were brought to Ulster as gallowglasses or hired soldiers to fight on behalf of a Donegal chief in the mid 13th Century. By the 14th Century three septs of M(a)cSweeney had established themselves in Tirconnel (County Donegal). These were: MacSweeny Fanad, MacSweeny Banagh and MacSweeny na dTuath, popularly translated as "MacSweeny of the Battle-axes", though the words "na dTuath" actually mean "of the Districts" (in Tirconnell). A branch of the first named sept migrated to Munster, and took up arms on behalf of the MacCarthy chiefs about the year 1500. In turn, they were granted large tracts of land and fortified castles in Muscraidhe (Muskerry). The McSweeney Coat of Arms depicts a silver lizard on a green fess between three black boars passant, all on a gold shield, the Crest being an arm in armour embowed holding a battle-axe all proper. The first recorded spelling of the family name is shown to be that of Murrough MacSuibhne, which was dated 1267, in the "Annals of the Four Masters", during the reign of King Henry 111 of England, 1216 - 1272. 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.