Which emperor made Christianity the official religion of the Roman Empire in 380 CE?

Which emperor made Christianity the official religion of the Roman Empire in 380 CE?

• A. Constantine I
• B. Theodosius I
• C. Diocletian
• D. Julian the Apostate

Answer: (B)

The important idea is how an official faith is established by law. In 380 CE, Theodosius I, with the cooperation of Gratian and Valentinian II, issued the Edict of Thessalonica. This decree declared Nicene Christianity the only legitimate religion of the Roman Empire and called for the suppression of other religious practices. That moment marks Christianity becoming the empire’s official state church, legally recognized and supported by the imperial government. Earlier rulers like Constantine had favored Christianity and granted it tolerance, but Theodosius codified its status as the empire’s official religion.

The important idea is how an official faith is established by law. In 380 CE, Theodosius I, with the cooperation of Gratian and Valentinian II, issued the Edict of Thessalonica. This decree declared Nicene Christianity the only legitimate religion of the Roman Empire and called for the suppression of other religious practices. That moment marks Christianity becoming the empire’s official state church, legally recognized and supported by the imperial government. Earlier rulers like Constantine had favored Christianity and granted it tolerance, but Theodosius codified its status as the empire’s official religion.