h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

After Tutankhamun was first exhumed in 1926 it was thought, because of x-rays, that he was killed by a blow to the back of the head with a blunt object. This was thought because there was something that looked like a blood clot on the x-rays and because there were what looked like fragments of bone floating around within the skull.

However, after the second exhumation in 2005 (roughly), and a CT scan (along with other technical jiggery-pokery), it was concluded that this was untrue, and that it was far more likely that a fracture to the left kneecap, possibly suffered because of a fall from a chariot, or sustained during battle, became infected, resulting in gangrene, fever throughout his body, and a slow and painful death.