Had Edward VIII not abdicated, he may well have died before 1972 - and Prince Albert, Duke of York (George VI) may have lived much longer due to not having the stress of being King during WWII. Therefore, if Edward VIII was indeed incapable of fathering children, and died in say the 1950s, he would have been succeeded by his younger brother Prince Albert, who would have become George VI anyway...only much later. When he died, say, in the 1960s-80s, presuming he had no sons (only Elizabeth and Margaret), Elizabeth would then have still become Elizabeth II. However, it is very questionable whether she would have married Prince Philip of Greece had her father not been King in 1947; therefore, she may have had either different children, or no children. In the latter scenario, all other things being equal, the present Duke of Gloucester would almost certainly be King Richard IV right now.