These soap tins (made of aluminium) were part of the 1944 British Army jungle kit, intended to protect the issue soap in tropical extremes....most seen today have 1945 dates and I doubt if any were seen in Europe until possibly the very end of WW2...
Not sure if a similar tin for the soap was issued prior to this for general use....steel or bakelite springs to mind...? I suspect most troops simply wrapped the soap up in paper wrapping and shoved it into their canvas personal kit roll...