This surname, of Irish origin, is the Anglicized form of the Gaelic "Mac Aodhagain", "Mac" meaning "son of" and "Aodhagain", from Aodha, which is a patronymic from the personal name "Aodh" meaning "fire", originally the name of a pagan god. The surname is really "Mac Egan", though the prefix Mac is rarely used in modern times, falling into disuse with the prefix "O" (male descendant of) during the period of Gaelic submergence, except by the family which claims to be the head of the sept. The Mac Egans were hereditary lawyers, that is, lawyers to ruling families originally a Brehon family of the Ui Maine (an ancient population group comprising mid-Galway and south Roscommon and Offaly (Ormond)). Following the destruction of the Old Gaelic order they held high office in the church, and the name became Anglicized as Keegan in Counties Dublin and Wicklow. Redwood Castle Lorrha, County Tipperary is the setting for clan Mac Egan rallies. One Anne Egan married Thomas Ghest in Dublin in 1582. Between January 1846, and June 1847, fifty-one Egans are known to have arrived in New York as famine immigrants. The first recorded spelling of the family name is shown to be that of Sarah Egan, which was dated 1226, marriage to Thomas Estrange, at Killaloe, County Clare, Ireland, during the reign of King Henry 111, "The Frenchman", 1216 - 1272. 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.