This ancient surname has two possible sources. Firstly, the surname may be of Anglo-Saxon origin, and a locational name from either of two places named Crowle. Crowle in Lincolnshire, recorded as "Crule" in the Domesday Book of 1086, is named from a river (now no longer extant, due to draining) deriving from the Olde English pre 7th Century "crull", curly, winding. Crowle in Worcestershire, recorded as "Croelai" in the Domesday Book, is a compound of the Olde English "croh", bend, with "leah", wood, clearing. 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 surname may also have originated as a nickname, deriving from the Middle English "crull(e), curl(e)", curly. The creation of surnames from nicknames was a common practice in the Middle Ages, and many modern-day surnames derive from medieval nicknames referring to personal characteristics, as in this instance the "curly haired one". William Curle was a witness in the Assize Court Rolls of Lincolnshire (1202). On July 3rd 1631, John, son of Edward and Frances Curl, was christened at St. Martin in the Fields, Westminster, London, and Ralph Curl married Elizabeth Lambden on June 5th 1648, at St. Margaret's, Westminster, London. The first recorded spelling of the family name is shown to be that of Burewoldus Crul, which was dated 1066, in the "Book of Winton", Hampshire, during the reign of King William 1, known as "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.