It is our desire that all the various nations which are subject to our Clemency and Moderation should continue to profess that religion which was delivered to the Romans by the divine Apostle Peter as it has been preserved by faithful tradition and which is now professed by the Pontiff Damasus [Bishop of Rome] and by Peter, Bishop of Alexandria, a man of apostolic holiness. According to the apostolic teaching and the doctrine of the Gospel, let us believe in the one deity of the Father, the Son and the Holy Spirit in equal majesty and in a holy Trinity. We authorise the followers of this law to assume the title of Catholic Christians; but as for the others, since in our judgement they are foolish madmen, we decree that they shall be branded with the ignominious name of heretics and shall not presume to give to their conventicles the name of churches. They will suffer in the first place the chastisement of the divine condemnation and in the second the punishment of our authority that in accordance with the will of Heaven we shall decide to inflict.
Theodosius the Great (347–395; recognised as a saint by the Orthodox) was born in Spain, the son of an army officer of high rank. He himself rose to high rank in the Roman army.
Up to the year 378, Gratian was Augustus in the West, with his minor brother Valentinian II as junior emperor. Their uncle Valens was Augustus in the East.
On 9 August 378, Valens was killed in battle against the Goths at Adrianople and Gratian thus became emperor of the whole empire. He appointed Thedosius commander of the army in Illyria. Since Valens had no successor, this made Theodosius de facto ruler in the East, and Gratian raised him formally to the imperial dignity as Augustus on 19 January 379.
The West was devoted to Nicene orthodoxy while the Arian heresy, promoted by Valens, was rife in the East. To establish orthodoxy throughout the empire and to suppress the Arian heresy, Gratian and Theodosius issued the Edict of Thessalonica on 27 February 380:
The edict was directed, not against non-Christians, but against Arian Christians. Theodosius summoned a council to meet at Constantinople in May 381, which was to be the 2nd Œcumenical Council. It reaffirmed the Nicene Creed and clarified the divinity of the Holy Spirit. Arian bishops throughout the East were replaced by orthodox bishops and Arians were expelled from Constantinople.
It is often said that the Edict of Thessalonica made Christianity the ‘official religion’ of the Roman Empire but this is misleading. It reflects a modern understanding of the world that had no meaning for people at the time. It is important to remember that, in all traditional societies, religion and government were inextricably intertwined—indeed, it is fair to say that government was a religious function. By the end of the fourth century the religion intertwined with the Empire was Christianity. This situation had developed over the course of a century. It was never ‘officially’ declared and did not need to be—it was simply an obvious fact.
Paganism was suppressed because it was the religion that had been traditionally intertwined with Roman government and it was necessary, now that it had become moribund, to disentangle it. As one example, the Olympic Games, which had always been a state function, were last celebrated in 393. Other faiths were not affected. A decree of 29 September 393 in the Codex Theodosianus declared, ‘The Jewish sect is protected by law. No synagogues shall be despoiled, and no regulation may be passed to ban Judaism, even in the name of Christianity.’
Occasional comments by a convert to Orthodoxy.