This most interesting and unusual surname is of Old Welsh origin, and derives from the Old Welsh personal name "Iorwerth", which is composed of the Welsh elements "ior", lord, and "gwerth", worth, value. This personal name is found in a variety of forms, ranging from "Yorwerth, Yorwarth" and "Yorward" in 1283, to "Yerward" in 1295, as well as "Yorworth" in 1301. As Iorwerth fell comparatively into disuse, it was replaced by Edward, especially in North-East Wales. In the Whittington register, there is mention of a placename Fernhill Yerwarth. In the medieval period the name "Gervase" was used occasionally in official papers for Iorwerth. Modern variants of the surname include Yorward, Yorwerth and Youarth. Yorath itself is widespread in the English counties surrounding Wales. The earliest recording of the personal name is Iorwerth Ap Bleddyn, Prince of Powys in 1110. John Yearoth married Margerett David on June 11th 1574 at St. Ishmael, Carmarthen, Wales; while Elizabeth Yorath married John Thomas on October 11th 1757 at Coychurch, Glamorgan, in Wales. The first recorded spelling of the family name is shown to be that of ... ap Iereward, Yereuarth (no known personal name), which was dated 1292, in the "Subsidy Rolls of Shropshire", during the reign of King Edward 1, known as "The Hammer of the Scots", 1272 - 1307. 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.