This is a medieval Scottish surname, locational in origin from a place in Fife which derives its name from the Old Scottish title "maister", master, with the Middle English "tune", village, settlement. The title "master" in Scotland was usually held by the eldest sons of barons. The lands in Fife now called "masterton" were once held by a tenant referred to in the Latinized form of "Magister Ailricus", who may be the "magister" or "master" after who the lands were named. One Duncan de Maysterton witnessed the homage of Duncan, Earl of Fife to the abbot of Dunfermline in 1316. Sir Thomas Masterton was a Canon of Cambuskenneth in 1476 and the Mastertons were a family of note in the Dunfermline district before the Reformation. The first recorded spelling of the family name is shown to be that of William de Mastetone, which was dated 1296, The Documents relating to Scotland in the Public Record Office, during the reign of King Edward I, 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.