This interesting surname is of Irish origin and is the Anglicization of the Gaelic O' Breaslain, possibly a derivation of the Gaelic word "bres" meaning strife, Breslin, although originally prefixed with "O", (denoting descendant of) is seldom found in modern times in this form. It is primarily a Donegal name, and the sept of O' Breislein, a branch of the Cenel Enda, possessed a district in the barony of Kilmacrenan called Fanad, where they were powerful chiefs, mentioned frequently in the Annals of the Four Masters. The O' Breslins were also one of the principal brehon families, and when the leading families migrated to County Fermanagh they pursued this profession and also became eranaghs (lay priests). John J. Breslin (circa 1836 - 1888) the Fenian who effected the escape of James Stephens from Richmond prison was of a County Tyrone family. The first recorded spelling of the family name is shown to be that of Margrat A. Brislan, which was dated November 24th 1667, Derry Catherdral, Templemore, during the reign of King Charles 11, "The Merry Monarch", 1660 - 1685. 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.