The Council of Florence, held in 1437-1441, sought to heal the East-West schism that was present in the Catholic and Orthodox churches. Papal political leverage afforded Eugenius IV the opportunity offer military aide to the deteriorating Roman Empire in exchange for ecclesiastical submission to the authority of Rome. The Emperor John VIII, and his delegates agreed, and a union was declared. Similarly, the heads of the Coptic, Ethiopian, and Armenian churches, also sent delegates to this convocation, perhaps the last council to truly call itself "ecumenical". In accord, they also signed bulls of Union with Rome, some of which remain in effect, some of which have been nullified in the subsequent centuries.