The Battle of Bosworth

On the morning of the 22nd August 1485, to the sound of thundering hooves, gunshot, the clash of steel and the cries of men in battle, Richard III, King of England, lost his life and the Platangenet line came to an end. But what do we really know of the battle which became known as the Battle of Bosworth Field? How do we separate fact from legend when our knowledge is based on sources which are meagre, garbled or partisan?