This warm-hearted, respectful film about Muhammad Ali lacks the originality and force of movies such as Leon Gast’s When We Were Kings (1996) or William Klein’s documentary Muhammad Ali: The Greatest (1969), and may be destined to wind up on the DVD memorabilia shelf of Ali fans. But it is impossible not to thrill to images of the man himself, and Clare Lewins has put together a very watchable tribute, with interviews and tape recordings Ali made with his family. And the film has one piercing insight: when Ali was banned from boxing from 1967 to 1971, these were not wasted years. On the contrary: he spent them on lecture tours, media appearances, photo shoots, cultivating his anti-war eloquence and burnishing the image. This was the crucial era in which Ali became the legend we now know. (It is incredible incidentally, to hear the condescension of some commentators around this time.) One is heard making a tiresome reference to Othello: “His occupation’s gone.”) An untold story is George Foreman’s transformation from a great lunk into the articulate media presence he is today. It was his religious conversion that did that, but might it not also have been the inspirational encounter with Ali himself – a secular boxing miracle in the jungle?

• Clare Lewins on I am Ali: rolling with the punches of Muhammad Ali’s life and myth