Why is it still 'Bloody Mary' but 'Bluff King Hal'?
Queen Mary I killed 284 people while Henry VIII executed as many as 72,000. Catholic Mary is always seen as an evil villain - while Henry VIII is still quite admired.
To read Gerald Warner's article on the subject in his Telegraph blog see:
blogs.telegraph.co.uk/news/geraldwarner/100047370/anti-catholic-junk-history-ii-mary-i-killed-284-henry-viii-up-to-72000-but-its-bloody-mary-and-bluff-king-hal/