Really? Because I've read otherwise that Constantine issued many an edict curtailing the rights of pagan religions in Rome that was continued under his successors, until banning them outright by making pagan services punishable by death.
I could have read wrong or received misinformation, though?
## No, your info was correct. Pagans were being persecuted in the 6th century, by the East Roman Emperor Justinian. Constantine & his successors - other than Julian - w. few exceptions made pagain rites illegal, even punishable by death. Theodosius made Catholic Christianity the religion of the Empire in 382.
In the West, Charlemagne gave the Germanic tribes a choice between baptism & death. Which is about as wrong as could be; it's a perfect example of confusing the demands of empire-building w/ those of faith. One of the evil results of imperial patronage of Christianity in was the idea that the religion of the subject must be that of the state, & vice-versa - in a Catholic Empire such as the Roman Empire officially became in 382, there is no room for Arians or other heretics. And in a Visigothic Arian state, which Spain was until 586, there is no room for Catholics. The Christian bodies wronged each other, & the Jews suffered no matter which Christianity was in power.
The relevance of that is, that the Christianisation - conversion is too stong a word - of the Roman Empire & the tribes, led to persecution of non-conforming groups Christian & non-Christian; the Catholics, now that they held the whip-hand, treated everyone else as they had been treated. IOW, not very well. The Arians were no better. The Donatists in Africa loathed the Catholics, and showed it by their actions. And the constant nastiness (& ambition) between Christians produced more & more heresies w/in the Empire, which helped to weaken it even more, b/c all these Christians were locked in a non-stop hate-fest.