Edict of Thessalonica makes Nicene Christianity the state religion
- Date
- 27 February 380 CE
- Category
- Religion & ideology
- Region
- Roman Empire (issued at Thessalonica)
- Era
- Classical Antiquity
- Significance
On 27 February 380 CE the emperors Theodosius I, Gratian and Valentinian II issued the Edict of Thessalonica (Cunctos populos), commanding all peoples of the empire to follow the Nicene faith professed by the bishops of Rome and Alexandria.
The edict defined adherents of the Trinity as 'Catholic Christians' and branded dissenting creeds, above all Arianism, as heresies deserving of punishment, both divine and imperial. For the first time a specific form of Christianity was established as the official religion of the Roman state, reversing the earlier policy of toleration and marking a decisive step in the Christianisation of the empire. Theodosius followed it with measures suppressing heresy and, in the early 390s, with laws prohibiting pagan sacrifice and public cult, effectively outlawing traditional polytheism. Incorporated into the Theodosian Code, the edict became a foundation of the medieval union of Church and state in both the Byzantine east and the Latin west, shaping the religious order of Europe for over a thousand years and setting the legal framework for the marginalisation of non-Nicene Christians, pagans and Jews.
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Empires active in 27 February 380 CE
- Sassanid Empire224 CE – 651 CE
- Kingdom of Funan50 CE – 550 CE
- Roman Empire27 BCE – 476 CE
- Byzantine Empire330 CE – 1453 CE
- Pyu City-States200 BCE – 1050 CE
- Gupta Empire320 CE – 550 CE
Related religion & ideology events
- First Council of Nicaea convenes325 CE
- Battle of the Milvian Bridge and the Edict of Milan28 October 312 – 313 CE
- Council of Chalcedon and the First Permanent Christian Schism8 October - 1 November 451 CE
- Judah ha-Nasi Codifies the Mishnahc. 200 CE
- The Kingdom of Aksum adopts Christianity under King Ezanac. 330s CE
- Nagarjuna Founds the Madhyamaka School and Systematises Mahayana Philosophyc. 150 CE
Further reading
The wider story
A Little History of Religion
Accessible sweep of humanity's faiths and belief systems from prehistory to the present.
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