The Maguire name is associated with modern-day County Fermanagh. They possessed the entire county, also known as Maguire’s Country, from about 1250 A.D. and maintained their independence as Lords of Fermanagh down to the reign of King James VI & I, when their country was confiscated like other parts of Ulster. The Maguires supplied Chiefs or Princes to Fermanagh, from about 1264, when they supplanted the former Chieftains (O’Daimhin, or Devin). They were inaugurated as Princes of Fermanagh on the summit of Cuilcagh, a magnificent mountain near Swanlinbar, on the borders of Cavan and Fermanagh; and sometimes also at a place called Sciath Gabhra or Lisnasciath, now Lisnaskea. The family was first mentioned in the Annals as early as 956 A.D. and have always been closely associated with the other leading septs of Ulster such as the O’Neill and the O’Donnell dynasties. They spawned several well-known branches which became septs in their own right, including Mac Manus, Mac Caffrey, Mac Hugh, and several others. The name is the single most common name in Co. Fermanagh. Maguiresbridge in Co. Fermanagh (Irish: Droichead Mhig Uidhir) takes its name from the family.
In the Nine Years’ War (1594–1603), Hugh Maguire, the Lord of Fermanagh, took the rebels’ side, while his subordinate kinsman Connor Roe Maguire of Magherastephana sought to displace him and was nicknamed “the Queen’s Maguire” for his support of Queen Elizabeth’s forces. Connor was granted the whole of Maguire’s Country (Fermanagh) by letters patent in 1601, but this was disregarded by the Plantation of Ulster in 1609, which granted him only twelve thousand acres of the barony of Magherastephana. Connor’s son Bryan was made Baron Maguire of Enniskillen in 1627; Bryan’s son Connor, 2nd Baron supported the Confederate Ireland rebellion of the 1640s and was executed and attainted in 1645. During translation in the Ulster Plantation, various English translations of the original Mag Uidhir appeared, including Mc Guire, Maguire, Mac Guire and McGuire. In South West Donegal, the name is re-translated into Gaelic as Mac Guibhir. An unusual version is Meguiar, an American spelling best known from “Meguiar’s Wax.”
The Maguire clan motto is “Justitia et Fortitudo Invincibilia Sunt”, which is Latin for “Justice and Fortitude Are Invincible.”