Born Cassius Marcellus Clay Jr, he was 21 years old when this photograph was taken, on a tour of England to fight British boxing legend Sir Henry Cooper. Cooper almost knocked Clay out with his trademark left hook dubbed 'Enry's 'Ammer'. Clay's armpit got caught in the ropes when he was falling down, and that is the only reason why his head did not hit the canvas. He was able to recover and eventually win the fight.
Muhammad Ali Clay went on to win his first World Heavyweight Championship a year later.