Introduction. The article is aimed at studying the negotiations on the Greek-Latin Church Union at the Church Councils in Constance (1414–1418) and Basel (1431–1449), which were the predecessors of the Council of Ferrara-Florence (1438–1439) in this matter. Since they were generated by internal processes in the Latin West, they originally had not direct relationship to Byzantium.
Methods and materials. The reason for the appeal of Councils to the problem of the Church Union should be sought in the field of Western international policy. It acted here as a tool for solving political problems by different actors.
Analysis. At the Council of Constance the discussion of the Greek-Latin Union was initiated by Poland and Lithuania, who used it as a means of political propaganda against the Teutonic Order. The Council of Basel subsequently entered into direct negotiations with Byzantium. The reason for this was at first internecine strife in the Duchy of Lithuania, which interfered with Poland, the Teutonic Order and King Sigismund. The Council initiated consideration of the Church Union in order to support the Lithuanian Duke Švitrigaila in the struggle for the throne. As a result Byzantium was included also in the negotiations with the Council of Basel. But in 1435 Švitrigaila was defeated in the clash with Poland and its ally Duke Sigismund Kęstutaitis. This defeat undermined the influence of Sigismund of Luxembourg at the Council of Basel. The King began his rapprochement with the Pope and Venice, and the Council of Basel was influenced by their political rivals, such as Milan and France. The theme of the Church Union at the Council became an instrument of struggle for political interests between these groups of political subjects. As a result, the struggle led to sharp disputes over the choice of the place for the Greek-Latin Council. The main options were Italy and French Avignon. The Byzantines chose the first option. But Byzantium was not the subject of the policy that created the situation of this choice. In the West this policy has led to significant changes.
Results. The results of the negotiations on the Church Union at the Council of Basel displayed the fall of the role of imperial policy in the Latin West, which was represented by the King and Emperor Sigismund Luxembourg. The Empire was losing control of Italy. The result was the withdrawal of the papacy from its influence and the strengthening of Venice. Their union stood behind the Council of Ferrara-Florence. Outside Italy this Council has not received recognition.
The Letters of Eljigidei, Hülegü, and Abaqa: Mongol Overtures or Christian Ventriloquism?
