The First Council of Constantinople, which affirms the Nicene Symbolum gives final form to the Nicene-Constantinopolitan Creed. The First Council of Constantinople is convened by Theodosius, the second ecumenical council, an effort to attain consensus in the church through an assembly representing all of Christendom, confirmed the Nicene Creed, expanding the doctrine thereof to produce the NicenoConstantinopolitan Creed