This ancient Lincolnshire surname is of Anglo-Saxon origin, and a locational name deriving from the place in Lincolnshire called Fosdyke. The placename is first recorded in the 1183 Pipe Rolls of the county as "Fotesdic", which shows clearly its derivation from "Fotes", the genitive case of the Olde English pre 7th Century byname "Fot", Foot, or the cognate Old Norse "Fotr" (genitive case "Fots"), with the Olde English "dic", ditch, dyke. The byname or nickname "Foot" would have been acquired by someone with some peculiarity or deformity of the foot, while the ditch or dyke referred to was, in the Middle Ages, considerably larger and more prominent than the modern ditch, and was usually constructed for purposes of defence rather than drainage. The surname has a number of variant forms, ranging from Fosdick and Fosdyke to Forsdyke, Forsdike, Forsdick, and, in Norfolk, Frosdick. One John Fosdyke is listed in the Suffolk Subsidy Rolls of 1524; Johannes Forsdicke was christened at Swanton Morley, Norfolk, on March 19th 1564; and Richard Forsdike married Mary Hamond at St. Steven's, Ipswich, on January 2nd 1719. The first recorded spelling of the family name is shown to be that of Walter de Fotesdik, which was dated 1202, witness in the "Assize Court Rolls of Lincolnshire", during the reign of King John, known as "Lackland", 1199 - 1216. 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.