The Book of the MacSweeneys (Lebor Clainne MacSuibhne) is one of only six bardic family historys/geneologies lodged in the Royal Irish Academy, and as such, is a work of great importance. The book itself was originally commissioned by the wife of one of the MacSweeney chiefs of Fanad (present Co.Donegal)and is therefore, historically suspect. The section dealing with the origins of the MacSweeneys is almost totally ficticious and needs to be carefully dissected and analysed in order to gain a real understanding of the clan's true origins. The claim of an ancient Irish (O'Neill) pedigree is, of course, complete nonsense. The reasons for these claims to an Irish connection are fairly obvious, as an O'Neill connection would certainly have smoothed their way into medieval Tyr Connaill at a time when there was likely to have been growing resentment at the influx of 'foreign lads', who were being cessed and billeted on their lands in Ulster.
The importance of this book lies in its recording of the family's history in Ireland, which clearly shows the MacSweeneys to have been the most important (and successfull) military aristocracy in British and Irish history. Only the Vangarian guard comes close to emulating their exploits. This is the history of my family, betrayed by English, Scots and Irish alike. Norsemen and nobles in origin, kings of Man and kings of the Gal-Gaedhil, the eponymous Suibne died in 1034, and not as the Irish annals repeatedly tell us, in the 1200's. Our true history is even more interesting than that of the book, but it reveals the ethos of a warrior caste who never took a backwards step.