Edict of Thessalonica

The Edict of Thessalonica (also known as Cunctos populos), issued on 27 February AD 380 by Theodosius I, made Nicene Christianity the state church of the Roman Empire. It condemned other Christian creeds such as Arianism as heresies of "foolish madmen," and authorized their punishment. This edict, addressed to the inhabitants of Constantinople whom Theodosius wished to pacify in order to make the city his imperial residence, constitutes the first known secular law which includes in its preamble a clear definition of what a Christian Roman ruler considers as religious orthodoxy, opening the way of repression against dissidents qualified as "heretics". The Edict of Thessalonica was subsequently incorporated into Book XVI of the Theodosian Code and was the milestone of the official Christianization of the Roman Empire. Background In 313 the emperor Constantine I, together with his eastern counterpart Licinius, issued the Edict of Milan, which granted religious toleration and freedom for persecuted Christians. By 325 Arianism, a school of christology which contended that Christ did not possess the divine essence of the Father but was rather a primordial creation and an entity subordinate to God, had become sufficiently widespread and controversial in Early Christianity that Constantine called the Council of Nicaea in an attempt to end the controversy by establishing an empire-wide, i.e., "ecumenical" orthodoxy. The council produced the original text of the Nicene Creed, which rejected the Arian confession and upheld that Christ is "true God" and "of one essence with the Father." However, the strife within the Church did not end with Nicaea, and the Nicene credal formulation remained contentious even among anti-Arian churchmen. Constantine, while urging tolerance, began to think that he had come down on the wrong side, and that the Nicenes—with their fervid, reciprocal persecution of Arians—were actually perpetuating strife within the Church. Constantine was not baptized until he was near death (337), choosing a bishop moderately sympathetic to Arius, Eusebius of Nicomedia, to perform the baptism.