So strong was Ambrose's hostility to some of the delegates that he described Basel as a western Babylon. He likewise supported the pope at Ferrara and Florence, and worked hard in the attempt to reconcile the Eastern and Western Churches. But in this council, and later, in that of Florence, Ambrose, by his efforts and charity toward some poor Greek bishops, greatly helped to bring about a union of the two Churches, the decree for which, 6 July 1439, he was called on to draw up.