The Metropolis of Kiev, Galicia and all Rus' was a metropolis of the Ecumenical Patriarchate of Constantinople in the Eastern Orthodox Church that was erected in 1441. The canonical territory was the western part of the traditional Kievan Rus' lands — the states of the Grand Duchy of Lithuania and the Kingdom of Poland. The episcopal seat was initially in the city of Navahrudak, which is today located in Belarus; later it moved to Vilnius in Lithuania. It was disestablished in 1595/6 with the creation of a new ecclesial body — the Ruthenian Uniate Church. Background An Ecumenical council of the Church — the Council of Florence — took place from 1431 to 1449. Although he resisted at first, the Grand Prince of Moscow — Vasily II of Moscow — eventually permitted the Metropolitan of Kiev and all Rus' — Isidore of Kiev — to attend the council on condition that Isidore should return with "the rights of Divine law and the constitution of the holy Church" uninjured. The council healed the Great Schism by uniting the Roman Catholic and Eastern Othodox churches. The union was proclaimed on 6 July 1439 in the document Laetentur Caeli which was composed by Pope Eugene IV and signed by the Holy Roman Emperor Sigismund and all but one of the bishops present. Some Greek bishops, perhaps feeling political pressure from the Byzantine Emperor, reluctantly accepted the decrees of the council. Other Eastern bishops, such as Isidore, did so with sincere conviction. Sylvester Syropoulos and other Greek writers charge Isidore with perjury because he accepted the union, despite his promise to Vasili II. Following the signing of the bull, Isidore returned to the Grand Duchy of Moscow. In the Kremlin's Dormition Cathedral, Isidore read the decree of unification aloud. He also passed a message to Vasili II from the Holy See, containing a request to assist the metropolitan in spreading the Union in Rus'. Three days later, Isidore was arrested by the Grand Prince and imprisoned in the Chudov Monastery. He arranged for certain Rus' clergy to denounce the metropolitan for refusing to renounce the union with Rome. As a result, the Great Prince of Moscow voided the union in his lands and imprisoned Isidore for some time. Having adjudged Isidore to have apostatized to Catholicism, he was deposed by a local synod. After the metropolitan throne lay vacant for seven years, the secular