This interesting and unusual surname is a variant of Caistor, which is of Anglo-Saxon origin, and is locational from a place so called in Lincolnshire. The name is derived from the Old English pre 7th Century "Caester, Ceaster", a Roman camp or fort. Locational surnames were developed when former inhabitants of a place moved to another area, usually to seek work, and were best identified by the name of their birthplace. The placename was first recorded as "castre" in the Domesday Book of 1086. The surname could also be a variant of Caister, which is locational from two places so called in Norfolk. The modern surname can be found as Caistor, Caister, Castor and Caster. Among the sample recordings in Lincolnshire are the marriage of Mark Kester and Elizabeth Johnson on January 24th 1614 at East Keal, and the christening of Daniell, son of Thomas and Anne Kester, on October 7th 1659 at Spalding. The first recorded spelling of the family name is shown to be that of Christopher Caster (christening), which was dated 1540, Field Dalling, Norfolk, during the reign of King Henry V111, "Good King Hal", 1509 - 1547. 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.