As with many Old English personal names such as "Alfgar" composed of the disparate elements "aelf", elf, and "gari", spear, most double-barrelled names are the result of a marriage between two families, where the resulting name has no overall meaning, but the separate elements have their own meaning and derivation. In this instance, this interesting surname Thornton, is of locational origin from any of the several places so called, in, for example, Lancashire, Lincolnshire and Yorkshire, and derives from the Old English pre 7th Century "thorn", meaning a thorn bush or hedge, with "tun", an enclosure or settlement, hence, enclosure by the thorn bushes. Dewhirst is a Lancashire locational name from a so called "lost" village, thought to have once been situated near Wilpshire, Lancashire. The name translates as "the wood", from the Old English "hyrst", or "Dew", a personal name, a variant of David. The first recorded spelling of this fame is Adam del Dewyhirst (1332). The first recorded spelling of the family name is shown to be that of Beatrice de Thornton, which was dated 1202, The Fine Court Rolls of Yorkshire, during the reign of King John, known as "Lackland", 1199 - 1216. 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.