This unusual and interesting surname is of Anglo-Saxon origin, and is locational from a place so called in the West Riding of Yorkshire. The placename is thought to derive from the Olde English pre 7th Century "hleotha", the dative plural of "hlith", slope, and "leah", wood, clearing, and was first recorded as "Ledelai" in the Domesday Book of 1086, as "Leeleia" in the 1166 Pipe Rolls of the county, and as "Lethelaye" in the 1291 Ecclesiastical Tax Records. 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 modern variants of the surname include Leathlay, Lethlay, Lethley and Leythley. Among the recordings in Yorkshire Church Registers are the christening of Thomas, son of Thomas Leathley, on August 12th 1604, at Ripon, and the marriage of Robert Leathley and Susanna Craven on October 23rd 1649, at Leeds. The first recorded spelling of the family name is shown to be that of John Leythley, which was dated May 10th 1552, marriage to Margaret (no surname), at Aldborough near York, Yorkshire, during the reign of King Edward V1, known as "The Boy King", 1547 - 1553. 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.