Council of Florence Declares Union

July 6, 1439

The Greek Orthodox hierarchy, desperate for Western military help against the Ottomans, signed an act of union with Rome acknowledging papal supremacy. The deal was a political fiction; Constantinople's streets rioted when the bishops returned. The union lasted as long as the Byzantine Empire: fourteen more years. The philosopher Bessarion, supporting the union, later donated his Greek manuscripts to Venice, creating a foundational library of Western humanism.