This is usually an Irish surname. Recorded as McCurley, McKerlie, McTerrelly, Curley, Kerley, Turley, Terry and others, and found particularly in the counties of Galway and Roscommon, it aparently derives from the ancient Mac Thoirdealbhoigh. This was composed of the prefix "mac", meaning son of, and the personal Viking name of "Thor," the God of Thunder, and a second element which means "in the shape of." This would give the translation of the surname as "In the shape of the god Thor. In the Census of Ireland in 1659 both McCurley and McTurley appear amongst the principal names in County Limerick. The places Ballymacurley and Curleys Islands are both found in County Roscommon, thus emphasising the connection of the name with that area. The name is also recorded in surviving church registers of the city of London when on October 21st 1621 Sara Curley was christened at St. Botolph without Aldgate, whilst at St. Peters Drogheda, County Louth, Gerald Kurley married Mary White on February 5th 1748. The first recorded spelling of the family name may be that of Syslay Kerley. This was dated February 18th 1569, when she was christened at St. Andrew's Holborn, in the city of London, during the reign of Queen Elizabeth 1st, 1558 - 1603. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as the Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.