O’Rourke, ó Ruairc A Gaelic surname meaning descendant of Ruarc. The personal name Ruadhrac came from the Norse Hrothrekr. The leading sept of Breifne (Breffny). Three of their ancestors in the tenth and eleventh centuries were Kings of Connaught. As lords of Breifne (Breffny) their territory extended from Kells in Meath to Drumcliff in Sligo. In the twelfth Century their power declined, with ó Raghallaigh (O’Reilly) becoming lord of east Breffny. They took a leading part in the Elizabeth wars and were only dispossessed with the Cromwellian confiscations. A sept of Uí Mhaine in Galway. A sept of Lia Con in the Barony of Tireragh in Sligo. A sept who were erenagh of Termonn Feichin, at Ballysadare, Sligo. In 1890 O’Rourke was the ninety-eight most numerous surname and the estimated number of bearers was 8,300. In that year the surname was chiefly found in Dublin, Leitrim, Roscommon and Wexford. In the United States O’Rourke is the 2,393rd most numerous surname with an estimated 13,750 bearers, and Rourke was the 8,171st most numerous surname with an estimated 2,750 bearers.