Great biographies try to answer questions about the complicated relationship between their subjects’ inner life and outer workings. How did Winston Churchill turn the pain of his early life and his years in the political wilderness into the words that galvanised the free world? How did Frida Kahlo’s physical impairment shape her vision as a painter?

I am endlessly interested in the inner and outer lives of the African–American writer and activist James Baldwin, for my money not just the most important black writer of the past 100 years, but one of the most important American writers ever.