The Norman expansion in eleventh-century Europe was a movement of enormous historical importance, which saw men and women from the duchy of Normandy settling in England, Italy, Sicily and the Middle East. The Norman establishment in the South is particularly interesting, because it represents the story of a few hundred mercenaries who managed to establish a principality in the Mediterranean that would later develop in to the Kingdom of Sicily. In this book the author examines the clash of two different "military cultures" - the Normans and the Byzantines - in one theatre of war - the Balkans. It is the first study to date of the military organization of the Norman and Byzantine states in the Mediterranean, and of their overall strategies and their military tactics in the battlefield. It is also the first to examine the way in which each military culture reacted and adapted to the strategies and tactics of its enemies in Italy and the Balkans. The author closely follows the campaigns conducted by the Normans in the Byzantine provinces of Illyria and Macedonia and their battles against Imperial armies commanded by the Byzantine Emperor. He also examines the ways in which the Italian-Norman and Byzantine military systems differed, and their relative efficiencies. Dr Georgios Theotokis is Assistant Professor of European History at Fatih University, Istanbul.