This unusual surname is of early medieval English origin, and belongs to that sizeable group of early European surnames that were gradually created from the habitual use of nicknames. These nicknames were originally given with reference to a variety of personal characteristics, such as physical attributes or peculiarities, and to mental and moral characteristics. The derivation in this instance, is twofold, being either from the Northern Middle English "sleght, slyght", smooth, slim, or from the Middle English "slegh, sleghth", craft, cunning, dexterity, both ultimately from the Old Norse. The two terms have now run together indistinguishably as if from the same source. Early examples of the surname from England and Scotland include: Thomas Sleh, Slei or Slegh (Lincolnshire, 1219); Robert Sley (Warwickshire, 1221); John called Sleth, burgess of Aberdeen in 1271; and Andrew Sleth, burgess of the same city in 1275. In the modern idiom the name has several spelling variations ranging from: Slay, Slee and Sly, to Sleigh, Sleith, Slight and Sleath. On May 3rd 1770, John Sleath and Anne Rowe were married at Northwich, Cheshire. John Sleath (1767 - 1847), noted in the "Dictionary of National Biography", was high master of St. Paul's School, London, 1814 - 1837. A Coat of Arms granted to the family is a gold shield with three red escallops in chief, the Crest being a gold crane. The first recorded spelling of the family name is shown to be that of Walter Sleh, which was dated 1219, in the "Feet of Fines of Essex", during the reign of King Henry 111, known as "The Frenchman", 1216 - 1272. 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.