More words have been written about Muhammad Ali than almost anyone else. He was, without doubt, the world’s most-loved sportsman. At the height of his celebrity, he was the most famous person in the world. And yet, until now, the one voice missing belonged to the man who knew him best—his only sibling, and best friend, Rahaman Ali.No one was closer to Ali than Rahaman. Born Cassius and Rudolph Arnett Clay, the two brothers grew up together, lived together, trained together, travelled toget...