Admittedly, their freewheeling boxing documentary is a little rambling and understructured, but nevertheless director Steve Read and producer-narrator Robert Douglas (both Brits) end up making a compelling and illuminating mosaic about the sport by focusing on an eclectic range of figures, some interviewed on screen. The opening sequence, narrated by Douglas, starts with his personal recollections about how much watching boxing meant to him, especially as a biracial kid from the roughest parts of Liverpool. He ended up living in one of Philadelphia’s seamiest neighbourhoods where he felt right at home, and this leads into a portrait of young boxers at an inner-city Philly gym where training and competing have opened up whole new worlds for young men who otherwise might have been sucked into the violence of the streets.

Then the film starts going off in all kinds of directions. There’s a digression about legendary boxing promoter Don King and his impact on the business, then a goodly chunk of time spent with charismatic former champ Bernard Hopkins who held world titles in two different classes but only started boxing when he came out of prison. (He did time for robbery, although apparently he never needed a weapon to persuade people to give him anything he wanted, so terrifying was his glower.) Hopkins visits some of the old neighbourhoods where locals hail him as a hero; then it’s on to an assortment of old pros who fought or sparred or just knew Muhammad Ali. This motley crew includes Larry Holmes, who defeated Ali in the Greatest’s penultimate bout before retiring, the Spinks brothers Michael and Leon, and Tim Witherspoon, AKA Terrible Tim, with whom Ali would spar in training at Deer Lake in Pennsylvania, a much loved facility out in the sticks.

While it’s apparent that boxing has taken its toll on several of the interviewees in neurological terms, most of them are charming raconteurs who witter on engagingly about their glory days. Meanwhile, Read, acting also as the film’s cinematographer, has an eye for interesting compositions, and the film teems with striking and atmospheric shots of neon lights at magic hour or people just hanging out in the streets, injecting themselves openly. The jazzy song over the closing credits, It’s the Peace that Deafens, written and sung by Ola Onabulé, was so lovely I bought that album.

• In the Company of Kings is on digital platforms from 30 April.