Raffaele D'Amato is an experienced Osprey author having written more than 20 titles. He is the author of 40 books on the military history of the Roman Empire, Middle Ages and Byzantium, as well as numerous articles. Having obtained his doctorate in Byzantino-Roman Law and Roman Archaeology, he taught for two years at the Fatih University of Istanbul as visiting Professor and is now working as a lawyer and as external researcher for the Laboratory of the Danubian Provinces of the University of Ferrara.

Andrea Frediani was born in 1963 in Rome, where he still lives and works. After graduating in Medieval History, he started a long-standing contribution to the prestigious Italian magazines Storia e Dossier, Medioevo, Rivista storica, Focus Storia and Focus Wars. He has published numerous works of non-fiction on the subject of military history and in 2007 published his first work of fiction, which became a bestseller in Italy. Since then he has written a number of historical novels including the Invincible series and the Dictator trilogy. His works have been translated into five languages.

Florent Vincent was born in 1973, and studied Applied Arts, History of Art and Archaeology. An illustrator specializing in historical and military subjects, he works with many French and Foreign publishers and museums (Museum of National Antiquities of St-Germain-en-Laye, Museum of the Army of Paris, Archaeological Museum of Frankfurt, etc.). He is also the co-author of two books on the Gallic Wars.

Civil war in the Western Roman Empire between AD 350-53 had left the frontiers weakly defended, and the major German confederations along the Rhine - the Franks and Alemanni - took advantage of the situation to cross the river, destroy the Roman fortifications along it and occupy parts of Roman Gaul. In 355, the Emperor Constantius appointed his 23-year-old cousin Julian as his Caesar in the provinces of Gaul with command of all troops in the region. Having recaptured the city of Cologne, Julian planned to trap the Alemanni in a pincer movement, but when the larger half of his army was forced into retreat, he was left facing a much larger German force outside the walls of the city of Strasbourg. This new study relates the events of this epic battle as the experience and training of the Roman forces prevailed in the face of overwhelming German numbers.