US President Barack Obama:

“Muhammad Ali shook up the world. And the world is better for it. We are all better for it.

“Muhammad Ali was The Greatest. Period. If you just asked him, he’d tell you.

“But what made The Champ the greatest, what truly separated him from everyone else, is that everyone else would tell you the same thing. “We mourn his passing but we’re also grateful to God for how fortunate we are to have known him.” The President, who has a pair of Ali’s gloves in the White House, referred to the picture of him “roaring like a lion” just after he had knocked out Sonny Liston to become world champion at 22.

He said: “He was still Cassius Clay, yet to set out on a spiritual journey that would lead him to his Muslim faith, exile him at the peak of his power, and set the stage for his return. ‘I am America’, he once declared. ‘I am the part you won’t recognise. But get used to me – black, confident, cocky; my name, not yours; my religion, not yours; my goals, my own. Get used to me’.”

Mr Obama added: “Later, as his physical powers ebbed, he became an even more powerful force for peace and reconciliation.

“He visited children with illness and disability around the world telling them they, too, could become the greatest.

“We watched a hero light a torch. We pray he finally rests in peace.”