More words have been written about about Muhammad Ali than almost anyone else. And yet, until now, the one voice missing has been the one belonging to the man who knew him best.

Muhammad Ali was, without doubt, the world's most-loved sportsman and people. At the height of his celebrity he was the most famous person in the world. And no one was closer to him than Rahaman Ali, his only sibling and best friend.

Born Cassius and Rudulph Valentino Clay, the two brothers grew up together, lived together, trained together, travelled together, and fought together in the street and in the ring.

A near-constant fixture in his famous sibling's company, Rahaman saw Ali at both his best and his worst: the relentless prankster and the jealous older brother, the outspoken advocate and the devoted family man. From time spent relaxing together behind closed doors, to encounters with kings, presidents and celebrities, he is able to offer an insider's perspective on all the well-known stories as well as never-before-told tales.