This unusual name, with the variants Dow, Dove and Dew, is of Scottish (and sometimes Irish) Gaelic Origin, and is the Anglicized form of the Gaelic word "dubh", dark, black, in Old Gaelic "dub". This word was frequently used as a personal name, by itself or as a shortened form of a longer double-stemmed name, and as a nickname or byname for a swarthy man, or perhaps for someone of a "dark" temperament. The patronymic form of the name is "MacDuff" or "McDuff", meaning "Son of Duff". In 1341 Brokynus Duff was one of an inquisition on lands in Aberdeen, and in the following year Machabeus Duff is on record as burgess of Cullen in 1342. The marriage of James Duff and Margarett Still was recorded at St. Margaret's, Westminster, in London, on March 16th, 1645. The first recorded spelling of the family name is shown to be that of Duncan Duff (witness), which was dated 1275, in the "Charters of the Priory of Beauly", during the reign of King Alexander 111, King of Scotland, 1249 - 1286. 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.