This is an Anglo-Scottish surname recorded as Slassor, Slesser, Slessor and Sletar. The origins are very obscure and no absolutely satisfactory explanation has been provided, although suggestions have been made that it may have been Dutch. It would also seem to be either occupational or locational, and describe either somebody who was a skilled worker, hence the agent suffix '-er', or possibly was locational from a place called 'Sless' or similar. Unfortunately there does not appear to be or to have been any such place in any of the known gazetters and maps of the last five centuries. We therefore conclude that it is occupational, and the first recording as shown below would seem to be the link spelling. We believe that this surname may be a dialectal tranposition from the famous name Slater also found in Scotland, through Slatter and Slettar to the modern forms usually Slessor. Over the centuries as people moved about to further their career or simply to survive, they recorded their births, deaths and marriages as they went along. Spelling upto quite recently being at best indifferent, and local dialects very thick, lead to the development of 'sounds like' spellings. Some of these were far removed from their original form, an example being the North Eastern name Cruddas or Cruddis which is from the famous Scots name Carruthers. In this case early examples of the surname recording taken from the surviving church registers of the diocese of Greater London include Mary Sletar at St Martins in the Field, Westminster, on March 28th 1715, and John Slessor, who married Mary Bristow, at St James Westminster, on August 3rd 1778, and Sir John Slessor M.C., was a famous RAF air marshall in the Second World War.