In A. D. 257, 1260 years before the time of Luther, Stephen, Bishop of Rome, began to act the pope in good earnest,--excommunicating those who dissented from the doctrines of Rome.
In 312, 1260 years before the massacre of St. Bartholomew in 1572, Constantine became Emperor of Rome, embraced Christianity, and terminated the last and bloodiest of the Pagan persecutions--that of Diocletian, which had continued ten years. Constantine undertook to remodel the church, in conformity to the government of the state, and the unhallowed union of the two resulted in the dignities of patriarchs, exarchs, archbishops, canons, prebendaries, &c., which he endowed with wealth and worldly honors.
While paganism was superseded by Christianity under Constantine, its ceremonies were not suppressed. The senate was still pagan; and "the title, the ensigns, and the prerogatives of Sovereign Pontiff, which had been instituted by Numa, and assumed by Augustus, were accepted, without hesitation, by seven Christian emperors."--_Gibbon_, v. 2, p. 183. Gratian became emperor, A. D. 376, and was the first who refused the pontifical robe. In 378, he invested Theodosius with the Empire of the East; under their rule paganism was "wholly extirpated," and the senate was suddenly converted.--_Ib._ That which hindered was thus taken out of the way. In 378, also, Gratian refusing the office, Damasus, the Bishop of Rome, was "declared Pontifix Maximus,"(4) and made "the sole judge in religious matters." All who would not adhere to the religion "professed by the Pontiff Damasus, and by Peter, Bishop of Alexandria," were declared heretics.--_Gibbon_, v. 2, p. 156. Damasus, by virtue of his power, introduced the worship of the saints, and of Mary, "the mother of God,"--excommunicating those who dissented. Thus the apostasy, by adopting the gods of the heathen, and the name of the heathen pontiff, began to be set up, and the excommunicated church disappeared in the wilderness.
In the ninth century a document was produced, which claimed to be a deed of gift from Constantine to the Pope, dated A. D. 324, ceding him the city of Rome and all Italy, with the crown, the mitre, &c.; but the forgery of this has been fully exposed. With the removal of the capital of the world to Constantinople, the empire began to decline; but the church augmented as fast. A provisional synod at Sardica, in A. D. 344, and a decree of the Emperor Valentinian III., in 445, had acknowledged the Bishop of Rome as the primate of the five patriarchs, and as the last tribunal of appeal from the other bishops; but the edicts of the Pope were often disregarded and opposed, and he continued subject to the civil power till the subversion of the Western empire by Odoacer, King of the Heruli, in A. D. 476.