The Mag Uidhir (McGuire/Maguire) are first mentioned in the Annals in A.D. 956, but "Where" did they come from? And "who" are the branches or septs that developed? I have a hypothesis that the Mag Uidhir line has been around Lough Erne since before the first Milennia began based on our Y DNA, specifically a SNP called R-Z16340. The upstream line of SNPs are: R-P312/S116 > Z290 > L21/S145 > DF13 > L513/S215/DF1 > S5668 > Z16340 Why is this important? Because the Mag Uidhir line is THE ONLY IRISH entity to share this SNP with a group of Belgian and Swedish men...all of which point to a tribe known as the Menapii circa 200BC-200AD. The lived in the marshes around the river's mouth and along the Dutch/Belgian/French coasts. They were traders and raiders long before the term "Viking" became widespread. And based on the root word for Fermanaugh (Fear/Fir Manach - aka: Men of Manach [ Menapia ]) there appears to be a linguistic connection that supports this. The Mag Uidhir line rose to great power in the later part of the thirteenth century, and became lords of Fermanagh, where the town and castle at Maguiresbridge recalls their importance there. They were long one of the most powerful and influential families in Ulster, and produced many great soldiers and ecclesiastics. During the reign of James I, in the first part of the seventeenth century, much of the territory of the Maguires was included in the vast confiscation of Ulster which followed the English conquest of the north. More land loss followed in the Cromwellian and Williamite confiscations, for the Maguires were ardent Jacobites, and later they were prominent among the Wild Geese in the service of France and Austria. As barons of Enniskillen their chiefs were accepted as nobility at the Court of France until the title became "extinct" about 1795. The MacManuses (Mac Maghnuis) descend from Maghnus, son of Donn Maguire, chief of Fermanagh, who died in A.D. 1302. The head of this family resided at Senadh Mic Maghnusa, now Bell Isle, on Lough Erne. The O’Cassidys (O Caiside) were a distinguished medical family, being the hereditary physicians to the Maguires. They also provided ollavs (professors or learned men) to the Maguires, and one, Rory O’Cassidy, Archdeacon of Clogher, is said to have participated in the compilation of the Annals of Ulster under Cathal Maguire in the fifteenth century. The first literary figure of the name was Giolla Moduda O Caiside, who died in 1143, and whose Gaelic poetry is still preserved. Before the end of the sixteenth century, branches of the family had settled in the Midlands around County Westmeath. The O’Corrigans (O Corragain) were an ecclesiastical sept closely related to the Maguires, and men of the name long filled abbacies and other church offices in County Fermanagh. By the sixteenth century the name had already spread into Connacht and the Midlands. Other branches of the Maguires include the Clann Fearghaile or MacKernans (Mac Thighearnain), chiefs of the territory called Clann Fearghaile in central Fermanagh, and the MacAuleys (Mac Amhlaoibh), who gave their name to the barony of Clanawley in west-central Fermanagh. A branch of the latter settled in Connacht under the form Gawley (Mag Amhlaoibh).