This interesting surname is the Anglicized form of the Gaelic-Irish name "O'Braion", descendant of "Braon", a byname meaning "moisture", "drop". At the present time, the name Breen is widely distributed throughout Ireland. Originally there were two septs of Breen, Mac Breens and O' Breens. The Mac Breen sept were located near Knocktopher, County Kilkenny, though by 1659, the prefix "Mac" (son of) had been dropped. The O'Breens, from "O Braoin", the greater sept, possessed territory in the counties of Westmeath and Offaly (near Athlone), where Breen is seldom met today, but is disguised under the alias "O'Brien". The surname dates from the 11th Century. Donal O'Breen was Bishop of Clonmacnois from 1303 to 1324. As late as 1421, one O'Breen of Brawney is mentioned in a contemporary document with O'Connor and Mac Morogh as a great chieftain of the Irish nation. Denis Breen a famine immigrant, twenty four years and a farmer left Glasgow on the ship "John R. Skiddy" for New York on November 4th 1846. The first recorded spelling of the family name is shown to be that of Tighearnach O'Braoin, (annalist who was abbot of Clonmacnois), which was dated 1088, in the Ecclesiastical Records of Clonmacnois, during the reign of High Kings of Ireland in opposition, (1072 - 1166). 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.