This interesting surname, of Anglo-Saxon and Old Scandinavian origin, is a variant of "Cawston", an English locational name from places so called in Norfolk and Warwickshire. The former appeared as "Caupstuna, Caustuna", while the latter placename in Warwickshire was recorded as "Calvestone", both in the Domesday Book of 1086. Both placenames have the same derivation, that is, from the Old Norse nickname "Kalf", calf, and the Olde English pre 7th Century word "tun", enclosure, settlement. The surname, which first appeared in the Domesday Book, is also found in the modern idiom as Cawston and Causton. William de Causton was recorded in 1125, in documents published in "Social Structure of Medieval East Anglia". "The Feet of Fines of Norfolk" mention one Richer de Causton in 1265, while Godfrey de Causton is recorded in the "Hundred Rolls of Norfolk" in 1273. Other early examples of the surname included the marriage of Agnes Cawson and John Iverye on February 17th 1560, at North Elmham in Norfolk; the christening of Alexander Cawson on November 19th 1564, at All Hallows the Loss, London; and the marriage of William Causon and Alese Newton on November 2nd 1612, in Norfolk. The first recorded spelling of the family name is shown to be that of Heroldus de Caustuna which was dated 1086, in the Domesday Book (Suffolk), during the reign of King Wilheim 1, known as "William the Conqueror", 1066 - 1087. 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.