Between Diocletian and Constantine, there was Galerius. This book offers a fresh study of this period, critical in the transformation of the Roman world. Using the political and personal relationship between the great emperor, Diocletian, and Galerius, his junior colleague and successor, the book comes to some quite different conclusions about the nature of Diocletian's regime than previously accepted. Drawing from a variety of sources--literary, visual, archaeological; papyri, inscriptions, and coins--the author studies the nature of Diocletian's imperial strategy, his wars, his religious views, and his abdication. The author also examines Galerius' endeavor to take control of Diocletian's empire, his failures, and successes, against the backdrop of Constantine's remorseless drive to power. The work is built from the premise that the "Tetrarchy", which Diocletian is often thought to have crafted as a revolutionary alternative to unstable military monarchy, is a creation of modern scholarship and does not actually emerge from the ancient sources. Instead, Leadbetter argues that Diocletian was seeking to craft a dynasty along more traditional lines, using adoption (as had so many of his predecessors) as a tool of statecraft. Galerius, however, did not prove equal to his inheritance, which was ultimately usurped by the more astute and ruthless Constantine. The first comprehensive study of the Emperor Galerius, this book offers an innovative analysis of his reign as both Caesar and Augustus, using his changing relationship with Diocletian as the principal key to unlock the complex imperial politics of the period.