This name is one of the most important and numerous of Irish surname. It derives form the Gaelic compound "Donn" meaning brown plus "cath" meaning battle and was applied to a "descendant of Downcha", Downcha being a personal name. The surname O Donnchadha is found under the variant Anglicised forms of O' Donoghue, O' Donohue, Donohue, Donaghy and Donahue. The O' Donoghues constituted an important sept in Kerry and associated parts of Cork in the ancient area known as Desmond. They had been driven into Kerry by the McCarthys where their chief territory was known as Onaght O' Donoghue. Other O' Donoghue septs existed in mid Galway and in County Cavan. The Onaght O' Donoghues split into two septs, the O' Donoghue Mor with its seat at Ross Castle near Killarney and O' Donoghue of the Glen entitled to the name "The O' Donoghue". Geoffrey O' Donoghue of the Glen a leading poet of the 17th Century who died in 1678. Among the early recordings in London is the christening of Elizabeth Donoghue on February 1779 at St. Botolph-without-Aldgate. The first recorded spelling of the family name is shown to be that of O Donnchadha of Jerpoint, which was dated circa 1150, in the "Ancient Annah of Kilkenny", during the reign of Turlough Mor O'Connor, High King of Ireland, 1119 - 1156. 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.