Book excerpt: The first modern account of the conflict between the eastern Roman Empire and the Sasanian kingdom. Greatrex traces the background to the war, investigating relations between Rome and Persia, the state of Roman defences in the East, and the chaotic situation in Persia at the end of the 5th century. He then examines the sources and the war itself, including the development of Roman defences, and the attempts by both powers to secure control of the Transcaucasian kingdoms.