The surname MacLaughlin, also spelt MacLoughlin and McLoughlin, is used in modern Irish as the anglicized form of an Olde Gaelic name borne by two entirely distinct Gaelic Septs, the first originally called O'Maoilsheachlann and anglicized as O'Melaghlin up to the end of the 17th Century assumed the name MacLoughun in 1691. The territory of this sept lay in the central plains of Ireland, especially in Co. Meath. The Gaelic prefix "O" indicates "male descendant of", plus "maol", the tonsured one i.e. a devotee of Saint Seachlann, an early Irish saint of the 8th century. This Maoilsheachlann from whom the family descends was better known as Malachy 11, High King of Ireland from 980 - 1002. The second MacLaughlin sept belonged to Innishowen Co. Donegal. The name means "son of (mac) Lochlann", a compound of the Norse elements "loch", a lake or fjord, plus "lann" land. The great leading men of this Sept are frequently referred to in "The Annals of the Four Masters". The Coat of Arms granted to the family has the blazon of per fess blue and red, in chief a gold lion rampant between two gold swords and in base three silver crescents. The first recorded spelling of the family name is shown to be that of MacLochlann of Ulster, which was dated circa 1200 in the Annals of Medieval History (Counties Donegal and Derry), during the reign of King Cathal, Craobhdhearg -known as Red Hand, High King of Ireland, 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.1198 -1224.