This rather unusual surname is of Irish origin, and is an Anglicised form of the Gaelic name "O'Ruaghagain", the prefix "O" meaning "male descendant of" or "grandson of", followed by the personal name "Ruadhagain", coming from the Gaelic element "ruadh", red. Traditionally, Irish family names are taken from the heads of tribes, revered elders, or from some illustrious warrior, and are usually prefixed by "O", as above, or "Mac", denoting "son of". The clan is of the Oriel sept which originated in Counties Armagh and Monaghan and parts of South Down, Louth and Fermanagh. Despite the similarity of spelling it has no association with the (O)Regan Clan. Recordings from Irish Church Registers include: the christening of Mary, daughter of Henry and Margaret Rogan, at Downpatrick, County Down on January 23rd 1799, and the christening of Ann Jane, daughter of Dan and Anne Rogan, at Aghalee, County Antrim, on December 25th 1813. One Anne Rogan, aged 17 yrs., was a famine emigrant to America, leaving Liverpool for New York in March 1846. The first recorded spelling of the family name is shown to be that of Elizabeth Rogan, which was dated 1743, christened at Inch by Gorey, County Wexford, during the reign of King George 11 of England, known as "The Last Warrior King", 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.1727 - 1760.