All of these positions and the almost innumerable variations on them which developed in the 4th century were strongly and tenaciously opposed by Athanasius and other pro-Nicenes, who insisted on the doctrine of "homoousion" or consubstantiality, eventually prevailing in the struggle to define this as a dogma of the still-united Western and Eastern churches for the next two millennia when its use was confirmed by the First Council of Constantinople. The struggle over the understanding of Christ's divinity was not solely a matter for the Church. The Roman Emperor Theodosius had published an edict, prior to the Council of Constantinople, declaring that the Nicene Creed was the legitimate doctrine and that those opposed to it were heretics.