This interesting surname is of English origin, and is locational from two villages and a hamlet named Thurlby in Lincolnshire, or from a town called Thoralby in the North Riding of Yorkshire, recorded as "Toroldesbi" in the Domesday Book of 1086. Both placenames derive from the Old Scandinavian personal name "Thorald", and "by" a village or homestead; hence "Thorald's homestead". The surname is first recorded in the latter half of the 13th Century (see below). Early recordings from English Church Registers include: the christening of Thomas son of Jhon Thurlby, on April 15th 1573, at Quarrington, Lincolnshire; the christening of William, son of Edmondi Thurlby, on October 28th 1600, at Washingborough, Lincolnshire; the christening of John, son of Thomas Thurlby, on February 23rd 1604 at Old Sleaford, Lincolnshire; and the marriage of William Thurlby and Jane Jaques on May 6th 1610, at St. Gregory by St. Paul, London. In the modern idiom, the name is also found with the variant spelling Thorlby. The first recorded spelling of the family name is shown to be that of Nicholas de Thurleby, which was dated 1273, in the "Hundred Rolls of Lincolnshire", during the reign of King Edward 1, known as "The Hammer of the Scots", 1272 - 1307. 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.