This Irish Sept are a branch of the O'Cahans, the former Lords of Keenaght, and one of the leading Clans of Ulster before the 16th century Scottish colonisation. The MacCloskeys are from Co.Derry and descend from one Bloskey O'Kane, slayer of Murtagh O'Loughlin heir to the Irish Throne in 1196. The names as McCloskey or McCluskey is also well known in America, Dr. K MacCloskey being Cardinal of New York in 1875. The first recorded spelling of the family name is shown to be that of Mac Bhloscaidh which was dated C1659, All Ireland Census during the reign of Richard Cromwell, The Lord Protector, 1658 - 1659 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.