This most interesting and unusual surname is of Anglo-Saxon origin, and is a topographical name for a dweller by a deep stream, deriving from the Olde English pre 7th Century elements "deop", deep, and "laecc", a stream or bog. The initial element "deop" is also found in the placenames Debden, Deepdale, Deptford, Depden, Dippenham and many more. Topographical surnames were among the earliest created, since both natural and man-made features in the landscape provided easily recognisable distinguishing names in the small communities of the Middle Ages. The surname first appears in Sussex in the early 14th Century (see below), while other early examples of the surname include the marriage of Annys Duplack and Thomas Wynter on October 19th 1592 at Isfield, Sussex; the christening of Thomas, son of Thomas Duplock, on February 18th 1612 at Newhaven, Sussex; the marriage of Robert Duplack and Elizabeth Moone on May 22nd 1652 at Heathfield, Sussex; and the marriage of John Duplacke and Joane Sharper on June 13th 1675 at St. Katherine by the Tower, London. Variants of the surname in the modern idiom include Diplock and Duplack. The first recorded spelling of the family name is shown to be that of John Depelak, which was dated 1327, in the "Subsidy Rolls of Sussex", during the reign of King Edward 111, known as "The Father of the Navy", 1327 - 1377. 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.