This is a variant spelling of the medieval "Dobbin" a name formed from the nickname "Dob" - a shortened form of Robert plus "kin", meaning "son of" or even "nephew of" of "Dob". The development to "Dubb" is dialectual, the name not apparently being recorded before the early 17th Century and even then being quite rare. The original name holder was probably John Dobyn of Cambridge, recorded in the Pipe Rolls of that county, later developments being Wylliam Dobbyns baptised at St. Margaret, Westminster in 1557 in the reign of Queen Mary (Bloody Mary, 1554 - 1558) and Susannah Dubbins who married Henry Jones at St. Mary Woolmouth, London in 1790. The first recorded spelling of the family name is shown to be that of William Dubbin. which was dated 1675, married Mary Williamson at St. Mary Le Bone, London. during the reign of King Charles II, The Merry Monarch, 1660 - 1685. 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.