In 1967, having embraced Islam and changed his name from Cassius Clay, Muhammad Ali refused to fight in the Vietnam war. "I will face machine-gun fire before denouncing Elijah Muhammad and the religion of Islam," he insisted. "I'm ready to die." As the reigning heavyweight champion of the world, and at the height of his dazzling powers, Ali was stripped of both his title and his licence to box.
Broke and vilified, Ali started calling Frazier, his eventual replacement as world champion. "He'd be phoning every other day to say, 'You got my title, man! You got to let me fight you!'" As he repeats that plea Frazier slips into an impersonation which sounds less like Ali in his fast-talking pomp than his old foe after Parkinson's disease had made his speech slurred and halting. "I said, 'OK, I'll see what I can do.'
"I went to see President Nixon at the White House. It wasn't difficult to get a meeting because I was heavyweight champion of the world. So I came to Washington and walked around the garden with Nixon, his wife and daughter. I said: 'I want you to give Ali his licence back. I want to beat him up for you.' Nixon said, 'Sure, I'd like that.' He knew what he was doing and so Ali got his licence back."
Ali had been in exile from the ring for three years before Frazier's intervention in 1970. Did Ali thank him? "I don't remember. Maybe he did - but I doubt it. I was just happy he got his licence back so I could clean him out."
Frazier had also given Ali money, but that did not stop the sudden animosity which welled up in the returning hero. Ali was initially amusing. "Joe Frazier is too ugly to be champ. He can't talk. He can't box. He can't dance. He can't do no shuffle and he writes no poems."
But the joking soon stopped. "Joe Frazier is an Uncle Tom," Ali ranted. "He works for the enemy."
Joe's son, Marvis, winces on the sofa opposite his father and me. "I used to get beat up every day at school by guys who would say, 'Your dad's a Tom'. It was terrible."