Charles Ignatius Sancho lived in Georgian London, where his adventures included meeting the king and writing and playing highly acclaimed music. Among the fun, he also became the first Black person to vote in Britain and led the fight against slavery. The story of this historical figure, largely untold before, has been brought to life by actor Paterson Joseph in his debut novel. Joseph, star of shows such as Noughts + Crosses, talks to historian David Olusoga about how the book began life as a one-man play and why Sancho’s story is best told through an epistolary novel.