Former United States president Bill Clinton has paid tribute to the courage Muhammad Ali has shown throughout his entire life, not just his boxing career. In celebrating his 70th birthday yesterday, the three-times heavyweight champion of the world is again back in the spotlight.

True Fighter: Legendary American boxer Muhammad Ali throws a
powerful left during his prime (1970). Ali celebrated his 70th birthday
Pic/Getty Images

Although renowned for being one of the greatest fighters the world has seen, Clinton feels Ali has fought his greatest battle over the past 18 years since being diagnosed with Parkinson's disease. "He made it (boxing) part theatre, part dance and all power. He was really something unique," Clinton told BBC Sport.

Bill Clinton

"And then when he risked it all to oppose the Vietnam war, in a funny way it could have destroyed him. But it didn't because people realised he had been very forthright and he was prepared to pay the price for his convictions. He could say 'I'm not mouthing off about this, this is the way I'm prepared to live and prepared to pay whatever the consequences are for standing up for what I believe in'.

"That, over the long run, made him even more fans. It's that kind of courage which he has manifested for as long as I've known him, and in dealing with his own illness. It took a sack full of guts to carry that Olympic flame up that ramp the last distance with his hands shaking in 1996 (in Atlanta), but he did it. And it's taken a lot of courage to continue to go out, to be seen, he wasn't self conscious. He's something special.

"One day when we were together it hit me -- and we have spent lots of time together over the last several years -- the courage he has showed, as an older man. Struggling with Parkinsons he has shown a different kind of, and perhaps a greater courage than he showed as a young man risking having his body, face and brain battered by the shock of boxing."