The Norse - Viking name 'Porbrorn' was popular as a personal name both with the original Viking invaders of the 8th Century and their later decendants, the 1066 Norman invaders. The name translates as 'Thor - warrior' which no doubt accounts for its later surname popularity and the wide range of both Scottish and English variant spellings which include Torbain, Thurbane and Turbayne (Scottish) and Thorburn, Thurban and Turbine (English). The name is first recorded in England as Richard Turbern (1198, Norfolk), the unusual variant of Turbayne appears to be a late arrival, an example being Isabella Turbayne who married William Black at Edinburgh Parish Church in 1868. The first recorded spelling of the family name is shown to be that of George Turbane, which was dated 1525, (witness) at St. Andrews, Fife, during the reign of King Henry VIII, 'Good King Hal', 1509 - 1547. 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.