Relations with the Kingdom of Sicily

The foreign policy of Michael VIII was determined, during the entire period of his reign, by his relations with the enemy Kingdom of Sicily. What he mostly endeavoured to avoid was an alliance between the king of Sicily, Manfred, and the Pope, against Byzantium. In order to achieve this, he depended chiefly on diplomacy, since the poor financial situation of the state did not allow him to undertake large-scale military operations.

The aversion felt by the head of the Roman Church towards the House of Hohenstaufen, who ruled in Sicily, initially facilitated matters for Michael, who, moreover, tried to tempt Pope Urban IV (1261-64) with proposals in favour of union of the Churches. But the situation changed in 1266, when, with the Pope's support, the brother of the King of France, Charles I of Anjou seized the state of Sicily and Southern Italy. In the following year (1267), with the support of Pope Clement IV (1265-68), Charles concluded the treaty of Viterbo against Byzantium with the titular emperor of Constantinople, Baldwin II. The other Greek, Latin and Slav states of the Balkans also signed this treaty.

The desperate situation in which Michael now found himself forced him to undertake intense diplomatic activity, mainly in the direction of the French King, who firmly believed that the most important task at that particular moment was the expulsion of the infidels from the Holy Land, not a war between Christian forces. The participation of Charles in the Crusade against Tunis called for by the King of France, Louis IX, in 1270, temporarily postponed the plans of the former with regard to Byzantium.