Move over Leonidas, here comes Michael Phelps

The American swimmer Michael Phelps will be looking for his 22nd Olympic gold medal when he competes in the 200m individual race at the Rio Olympics.

If he succeeds he will surpass the late, great Leonidas of Rhodes, a winner in the ancient Olympic games back in the second century BC.

Professor Paul Cartledge is a specialist in Greek culture and history at Cambridge University, and gave Martha Kearney some background to the great man.