Director William Nunez describes why he focused on a time when the poet Robert Graves – best known for a memoir Goodbye to All That and historical novel I, Claudius – left his wife and family in pursuit of creativity at any cost

How do you make the life of a poet work on screen? It helps if they had scandalous personal lives. Robert Graves was last seen on the sidelines of Terence Davies’s biopic as the friend of the first world war poet Siegfried Sassoon (Benediction). Now the tables are turned, with a cameo of Sassoon in a film about the early career of the man who would go on to become professor of poetry at Oxford and to win the Queen’s gold medal for poetry.

Graves is an unfashionable figure today, known chiefly through I, Claudius, the TV serialisation of two of his novels, starring Derek Jacobi as the Roman emperor.