This name is one of the most ancient and numerous family names in Ireland having the prefix "m(a)c" i.e., "son of". This great clan is of Scottish and Irish origin, created from a Gaelic personal name, "Donhnall", composed of the Celtic elements "dubno" world, "val" might, rule. The most numerous are the descendants of a Scottish clan from Argyle. They came to Ireland in the 13th Century and established themselves as gallowglasses (mercenaries) in the North of Ireland. Among the many distinguished bearers of the name in literature are Sean Clarach MacDonnell (1691 - 1754) supreme poet of Munster, and John de Courcy Mac Donnell (1859 - 1915), notable in Celtic studies. However, they are also a distinct Irish sept; by 1500 there were six McDonnell septs in Leinster. Another quite distinct sept of MacDonnells are those of Thomond, who were, before the Gaelic way of life was disrupted by invasion, bards to the O' Briens. Alexander McDonnell married Katherine White on December 19th 1683 at Londonderry, Templemore. The first recorded spelling of the family name is shown to be that of Sorley Boy MacDonnell, 1505 - 1590, which was dated circa 1550, in the "Irish Manuscript Commission", during the reign of King Edward 1st, known as "The Boy King", 1547 - 1553. 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.