9. The letters of the Roman bishops gradually came to be regarded in the Western Church as apostolic ordinances, and laid the foundation for the vast ecclesiastical legal system.[173:2] Siricius (384-398) wrote the first decretal which had the force of law.[173:3] A typical illustration of the character and power of papal letters is seen in the commanding communication of Pope Celestine sent in 428 to the bishops of Vienne and Narbonne concerning ceremonial abuses in their provinces. "Inasmuch," he wrote, "as I am appointed by God to watch over the whole Church, it is my duty everywhere to root out evil practices and to substitute good ones; for my pastoral superintendence is restrained by no bounds, but extends to all places where the name of Christ is known and adored."[174:1] The Gallic churches received this pronouncement without a whisper of disapproval. The Council of Chalcedon (451) accepted a letter from Leo I., settling a disputed point in theology.[174:2] Gelasius I. (494) instructed Emperor Anastasius on the superiority of the spiritual over the temporal power.[174:3] The decretals of Gregory the Great spoke with a bold, undisputed authority.[174:4] 10. The Edict of Milan in 313 did not make Christianity the state religion, but merely put it on a legal equality with paganism. It was not long, however, until this new status enabled Christianity to outstrip its old rival and actually become the constitutional faith. State patronage prepared the way for a conscious and natural adaptation and assimilation of forms of imperial polity. Accordingly the admonition of the early period assumed the tone of mandates; interferences, whether for advice or arbitration, took the character of appeals, rescripts, and ordinances; and the model of discipline and ritual for all churches emanated from Rome.