This unusual and interesting surname derives from the Old French male given name "Guarin", or Guerin", itself coming from the Old German "Warin", from the Germanic element "war(in)", guard. This name was popular in France, and among the Normans, partly as a result of the fame of the Carolingian lay "Guerin de Montglave ", and was initially introduced into England after the Norman Conquest of 1066. One Robertus filius (son of) Warin was recorded in the Domesday Book of 1086 for Cambridgeshire and a Gislebertus filius Garin(i) appears in the Domesday Book for Essex. Gilbert Warin, noted in the 1198 Curia Regis Rolls of Yorkshire, is the earliest recorded bearer of the surname in England. The name was subsequently introduced into Britain by French Huguenot refugees fleeing religious persecution in their own country, following the Revocation of the Edict of Nantes by King Lous X1V on October 22nd 1685. On July 26th 1696, Daniel, son of Francois Guerin and Janne Pater, was christened at Glasshouse Street and Leicester Fields French Huguenot Church, London. The surname is widespread in the Munster county of Limerick, and in County Kerry it takes the forms Geran and Gerin. The name is believed to have been introduced into Ireland by English settlers at an early date, but occasionally, it may be an Anglicized form of the Old Gaelic sept name "O Gearain", descendant of "Gearain", a byname meaning "sharp". The first recorded spelling of the family name is shown to be that of Didier Guerin, witness at a christening, which was dated February 15th 1585, at Loromon, Meurthe-et-Moselle, France, during the reign of Henry 111, known as "King of France", 1574 - 1589. 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.