Answer:
The Romans were polytheistic until Emperor Theodosius I converted the Empire to Christianity
Step-by-step explanation:
Rome was polytheistic for a long time – during its whole exitance BC and for the first few centuries AD. They adapted Greek religion and myths and had a strong appreciation of certain Greek gods, such as Apollo. In some parts, other culture’s gods were also appreciated, such as Cybele and Isis.
When Augustus became the emperor, strong support of the imperial cult started in Rome. The emperors were regarded as Gods. As Christianity started to emerge at that time, they declined to worship foreign idols, which is why Romans started prosecuting Christians.
Constantine, I was the emperor that ended the prosecution of Christians and the first Roman emperor to convert to Christianity.
Finally, with Theodosius I, Christianity was adopted as the state religion of the Roman Empire in 380 AD.