Recorded in many forms including Prop, Proop, Proops, Proffer, Proffor, Proper, Propper, Proppers, Priver, and Prover, this is probably a Welsh surname, or at least it may owe something to a Welsh ancestry. Surnames which are quite rare, which seem to have association with like spellings, and yet have confused recordings provide special problems. Some are unsolveable because there are not enough recordings to establish a pattern. Furthermore most, as with this one, are not recorded in any of the spellings in the national dictionaries of surnames. In our opinion from a study of the known records we have concluded that this is one of the names which originally commenced with the Welsh "ap" meaning "son of". This is cognate with the Gaelic Mac or Mc. In the late medieval period Wales adopted fixed surnames for the first time, long after other countries of the United Kingdom. In so doing they tended to fuse "ap" into the name. The most popular were ap Robert, ap Robin, ap Roger, and ap Rhydderch and these are known to have become Probert, Probyn, Proger, and Prothero as examples, but there may be others as yet unrecognized. Is Proop(s) from ap Rob, with p and b being interchanegable, whilst and Proffer and Propper seem close to ap Bobydd, with dd being pronounced "th". Examples of surname recordings taken from the rsgisters of Greater London include Roger Proffer at St Margaret's Westminster on December 17th 1591, David Proppe at St Mary Whitechapel, Stepney, on February 11th 1592, Valentine Priver at St Botolphs Bishopgate, on October 4th 1622, Guilelmi Proppers at St Martins in the Field, Westminster, on December 30th 1649, Mary Prover, at St Dunstans Stepney, on April 2nd 1689, and Annie Proops at St Phillips Stepney on June 27th 1870,