The Mask of Command is the fourth novel in the ‘Twilight of Empire’ series, set in the dramatic and dangerous world of the early 4 th century AD. With the Roman empire locked in civil war, Aurelius Castus is sent to the Rhine provinces to restore control over the threatened western border. But Castus soon discovers that the frontier is a place where the boundaries between civilisation and barbarism, freedom and slavery, honour and treason have little meaning. From the intrigues of the imperial court to the heat of battle, can he distinguish friend from enemy? Ian Ross has been researching and writing about the later Roman Empire and its arms for over a decade. He will be talking about his new book, the borders between history and historical fiction, and the process of research and imagination involved in recreating a distant era.