Background: Ryan comes from the Irish surname of O'Riain meaning descendant of Rian. The "O" in an Irish name means grandson. The Gaelic equivalent is Maoilriain and other variations include O'Ryan, Mulrian, Mulryan, and O'Mulrian. Ryan is still one of the most popular surnames in Ireland with an estimated 27,500 people using Ryan as their last name and it is the most popular surname in the Irish county of Tipperary which has a long history of Ryan's. The county of Tipperary was created in 1328 but Ryan's are prevalent in all counties of Ireland and were certainly around long before that. For instance O'Ryan, Prince of Idrone, was slain in the year 1170. Other important historical mentions of Ryan include: Sir Bernard Burke's 1863 book entitled "A Genealogical and Heraldic Dictionary of the Landed Gentry of Great Britain" which documents the Ryan Coat of Arms; and the town records of Marblehead, Massachusetts which show Timothy Ryan as having married on December 17th, 1688. Also, lesser known derivation of Ryan is from ancient Irish word "righin" meaning "sluggish" and it written as either Mulrian or O'Mulrian.