Recorded in various forms including Largan, Largen, Lergan, Lehrahan, Lerhinan, Lernihan, and Lerohan, this is a surname of Irish origins. It derives from the pre 10th century Gaelic O'Lairgneain or O'Loirgneain from "lorga" meaning variously a shin or shank, or a gaiter, or even a shin guard, in this case a piece of medieval armour. Most Gaelic surnames whether Irish or Scottish originate, from a (nick)name for the original chief. In this case the name was probably a reference to a chief who had either long or short legs, or given the humour of the medieval period and earlier, may equally have referred to a gentleman who wore distinctive gaiters! As Largan or Largen the surname is believed to originate in the former region of Oriel, which today is better known as Ulster or Northern Ireland, and particularly the area of County Armagh, whilst as Lerhinan or Lernihan the place or origin is given as County Mayo in the far west. In all cases the surname is considered to be rare, and one of the least common of all Irish surnames. Nethertheless it does appear in the infamous Famine Lists of 1846 - 1848, when over one million died and an estimated two million emigrated from the country. Amonst these emigrants recorded by the immigration department of the port of New York as having "arrived alive", were Bridget Lerohan, aged twenty, who embarked on the ship "John-Clark of Liverpool", on May 14th 1846, Ellen Lehrahan, aged twenty four and given as being a "labourer" who left only two weeks later on the ship "Mersey", and Rosa Largen, a servant, aged twenty three, who left Liverpool on the ship "Niagara" on October 1st of the same year.