Political and economic relations between Venice, Byzantium and Southern Italy (1081-1197)

This thesis analyses the evolution of the political and economic relations between Venice, Byzantium, and Southern Italy from 1081 to 1197. These years were mostly characterised by hostile relations between the Eastern Empire and the rulers of Southern Italy, which led to a series of conflicts. In the early ones, Venice fought alongside the Byzantines. This happened because Venice obtained significant commercial concessions in Romania, and worried that the same monarch might hold both shores of the Strait of Otranto, thus potentially hampering its Mediterranean trade. However, from the mid-twelfth century, the Byzantine attempt to acquire land in the Adriatic worried the Venetians, who thus decided not to help the Eastern Empire in its attempt to recover land in Southern Italy.
Even though, politically, Byzantine-Venetian relations had already worsened by 1155, the scale of Venetian trade in Romania kept increasing until 1171, when it suddenly stopped after the Byzantine decision to incarcerate all the Venetians who were in the Eastern Empire, and to have their goods confiscated. This measure led to a dozen years of hostility between the two, and to continued reciprocal scepticism, and to the strengthening of the political bonds between Venice and the Kingdom of Sicily.
After 1183, Venetian trade in Romania resumed (albeit on a limited scale), but the political bonds between Venice and Constantinople were only strengthened when the Byzantine Empire was facing serious military threats from the West. The best indication that a partnership between Venice and Byzantium could no longer be formed can be seen by looking at what happened in 1185. In this year, William II of Sicily followed in his ancestors’ footsteps by attacking the Balkans, and Venice did not intervene militarily alongside the Byzantines.