This interesting surname is an Anglicized form of the Gaelic Mag Eachagain. In Ireland the name is Geoghegan, which is hard to pronounce at sight, so it has many synonyms, and one of these, Gahagan, is a phonetic approximation of the longer and common form. The surname derived from the once common personal name "Oghy", with the initial "G" coming from the prefix Mag, a variant of Mac, meaning "son of"; hence "son of Oghy". The sept of the Mac Geoghegans is of the southern Ui Neill and of the stock of the famous sixth Century King Niall of the Nine Hostages; it was located in the present barony of Moycashel, Co. Westmeath, with the chiefs seat near Kilbeggan. These were of considerable importance up to the time of Cromwell when they suffered severely through war and confiscation. The surname is first recorded in the late 13th Century (see below). On October 25th 1691, Ann, daughter of Hew Gahagan, was christened at St. Patrick's, Dublin, and Lawrence Gahagan married Phebe Hunter, on June 7th 1762, at St. Pancras, Old Church, London. Brothers Lawrence and Sebastian Gahagan who were sculptors of note in London between 1760, and 1820, were Irishmen called Geoghegan at home. The first recorded spelling of the family name is shown to be that of Mac Geoghegan, chief of Cinel Fiachrach, which was dated 1291, "Annals of the Four Masters", during the reign of King Edward 1, "The Hammer of the Scots", 1272 - 1307. 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.