This book rediscovers a lost history of the Roman Empire, written by Sextus Aurelius Victor in the middle of the fourth century A.D. Though little regarded today, Victor was the most famous historian of his day, read by Jerome and Ammianus, honoured with a statue by the pagan Emperor Julian, and a prestigious prefecture by the Christian Theodosius. Our rediscovery of the original scope and scale of his Historia revolutionises our understanding of the writing of history in late antiquity, with profound implications for the study of Roman history and the transmission of the Classics.