One of the longest-lasting rumours that has surrounded Henry VIII for centuries is related to his physique. Because did the infamous womanising King have syphilis?
Since the King was notorious - even at his own day - for his many casual liaisons with many different ladies it is possible that he had caught a disease. The rumour even states that Henry's syphilis may have caused the miscarriages of Catherine of Aragon and Anne Boleyn and that the ulcer that plagued Henry throughout his life was a sign of the STD.
However, today the theory is no longer considered to be likely mainly because of the lack of evidences to support the statement. Also, syphilis was a well-known disease in the Tudor age and even if the King had had it, there would have been a cure.
So this is a rumour that we can quite safely say is untrue.