Who was Sauron?

I read LOTR for the first time as a teenager in the Seventies, and back then there was no doubt in my mind who Sauron was. An evil tyrant who wanted to dominate the World, it could only be Adolf Hitler. For years I always thought of Sauron as being a manifestation in Middle Earth of the bogey man I had grown up with. It wasn't until years afterwards that I realised that the whole concept behind the book predated the Second World War by many decades. (I know it is there in the foreword, so I have no excuses but that is the way it was.) The fact that Tolkien himself was clear that the War of the Ring was not an allegory of the Second World War did really register at the time. But now I have had time to think about and to know more about how long it takes for an idea to form, I realise that I was certainly wrong. Sauron could not have been modelled on Hitler. So if it wasn't Hitler who inspired Sauron, who was it? There aren't a great many characters in history who really fit the bill as a Sauron prototype. Stalin is eliminated on the same chronological grounds as Hitler himself. And in any case Stalin never really fitted the bill. Hitler was a charasmatic evil wizard like figure who really seemed to have some kind of demonic power. Stalin always comes across more as a bureaucrat than an inspirational leader. No doubt he was just as eviil, but not really as interesting. Tolkien fought in the First World War, and there are many echoes of that conflict in LOTR. Could it be that Sauron was a personification of Kaiser Wilhelm. I don't think this really stacks up. The Kaiser's personality is pretty weak and it wasn't really his willpower that motivated the German armies in the First War. I don't think that anyone outside of propaganda departments would ever really think of him as the embodiment of evil. I think the only real choice is Napoleon. Tolkien was English and would not have been an admirer of Napoleon. Napoleon has never had a good press in England. He attempted to conquer the World and did it with huge elan but also with a depth of ruthlessness and agility that match Sauron pretty well. His victories are so amazing as to be almost magical and his very personal style of leadership really brings to mind the way Sauron could move his troops to do his will. Napoleon, like Sauron, was compelled to capitulate after a titanic struggle. The battle of Waterloo must have seemed to Tolkien very much the way the Last Battle before the Barad-Dur is portayed. And when the British got their hands on Napoleon they were still so scared of his wizard like powers that they had to imprison him on an island miles from anywhere to avoid him making a comeback. It is a shame that Ar-Pharazon (check name) didn't think of that instead of taking him back to Numenor at the end of the Second Age. Interestingly, when the British got Napoleon onto one of their warships they were careful to keep him away from London and the Prince Regent. They were scared that his huge charisma would be sufficient to charm the Prince Regent. And once he had him under his spell who knows what further evil he get up to. When I heard that I instantly thought of the way Sauron was able to bewitch the king of Numenor and all his councilors.