This most interesting and unusual surname is of medieval Scottish origin, and is a topographical name from residence by a path near which a kiln for the drying of lime, or corn was situated. The component elements of the name are believed to be the Old Gaelic "sli", way, track, mountain path, with "aithe", from "aith", kiln or "sweat-house". Perhaps the reference here is to a remote mountain hut to which people repaired to cure or lessen the effects of a respiratory infection by sweating. Topographical features, whether natural or man-made, provided obvious and convenient means of identification, and consequently gave rise to many surnames. Regional and dialectal differences subsequently produced several variations in the spelling of the name; thus in the modern idiom spellings range from Shil(l)ito, Shillito(e) and Shilladay to Shilliday and Shelliday. On February 21st 1579, Elizabeth, daughter of Robart Shilleto, was christened at Allhallows, London Wall, London. The form Shilliday is particularly well recorded in Church Registers of Co. Down from the mid 19th Century. On January 23rd 1844, the baptism of Agnes, daughter of James Shilliday and Rachel Blakely, was recorded in Ballynahinch in that county. John Shilladay and Janet Mitchell were married in Kilmaurs, Ayrshire, Scotland, on June 7th 1861. The first recorded spelling of the family name is shown to be that of Adam Selito, which was dated 1379, in the "Poll Tax Returns 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.