This unusual and interesting name is of early medieval English origin, and derives from the Anglo-Norman French ethnic name used to distinguish someone from Germany or the Low Countries. The surname is first recorded during the 12th Century (see below), and derives from the Anglo-Norman word "tieis" or "tiois", meaning "German", the ultimate derivation being from the Old High German "diutisk", "tiutisc", from "diot", meaning "people" or "race". The modern surname is found as either Tyas or Tyers. The Charters of the Abbey of St. Mary, Clerkenwell, London, record one Fulbrich Tyes in 1236. The surname is found particularly well recorded in Yorkshire Church Registers: John, son of William Tyas, was christened at Dewsbury on April 3rd 1545, and the marriage of Nicholas Tyas and Helen Jubb was recorded in Wragby, on August 10th 1587. A Coat of Arms granted to a Tyas family of London depicts, on a white shield, a red chevron, on a canton, black, a cinquefoil pierced ermine. The Crest is a griffin's head erased silver beaked red. The first recorded spelling of the family name is shown to be that of Everard le Tieis, which was dated 1170, in "Sir Christopher Hatton's Book of Seals", during the reign of King Henry 11, known as "The Builder of Churches", 1154 - 1189. 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.