This interesting and most unusual surname has two possible interpretations, deriving from the same elements. Firstly, it may be a topographical name given to a dweller in a wide valley, or recess, from the Olde English pre 7th Century elements "sid", broad, spacious, and "halh", a nook, recess, remote valley. However, the name may also be of locational origin from any of the various places called "Siddall", such as those in the parish of Middleton, Lancashire, and near Halifax in Yorkshire. The placenames are composed of the Olde English elements as mentioned above. During the Middle Ages, when migration for the purpose of job seeking was becoming more common, people often took their former village name as a means of identification, resulting in a wide dispersal of the surname. Early examples include: John Sedall (London, 1547); Katherin Sydall (London, 1585); and Peter Sidell (London, 1594). Mary Sidle married Arthur Kay in 1656 at St. Mary's, Bury in Lancashire. Modern variants of the surname include Siddle, Sidell, Sydal and Sydel. The first recorded spelling of the family name is shown to be that of Thomas Sydall, which was dated 1379, in the "Poll Tax Records of Yorkshire", during the reign of King Richard 11, known as "Richard of Bordeaux", 1377 - 1399. 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.