Byzantine–Norman wars participant Kingdom of Sicily
Second Norman invasion of the Balkans (1147–1149)
In 1147 the Byzantine empire under Manuel I Comnenus was faced with war by Roger II of Sicily, whose fleet had captured the Byzantine island of Corfu and plundered Thebes and Corinth. However, despite being distracted by a Cuman attack in the Balkans, in 1148 Manuel enlisted the alliance of Conrad III of Germany, and the help of the Venetians, who quickly defeated Roger with their powerful fleet. In ca.1148, the political situation in the Balkans was divided by two sides, one being the alliance of the Byzantines and Venice, the other the Normans and Hungarians. The Normans were sure of the danger that the battlefield would move from the Balkans to their area in Italy. The Serbs, Hungarians and Normans exchanged envoys, being in the interest of the Normans to stop Manuel's plans to recover Italy. In 1149, Manuel recovered Corfu and prepared to take the offensive against the Normans, while Roger II sent George of Antioch with a fleet of 40 ships to pillage Constantinople's suburbs. Manuel had already agreed with Conrad on a joint invasion and partition of southern Italy and Sicily. The renewal of the German alliance remained the principal orientation of Manuel's foreign policy for the rest of his reign, despite the gradual divergence of interests between the two empires after Conrad's death. However, while Manuel was in Valona planning the offensive across the Adriatic, the Serbs revolted, posing a danger to the Byzantine Adriatic bases.