On this day in A.D. 380, the Emperors Gratian and Theodosius promulgated the Edict of Thessalonica, ending the conflict between orthodox Christians and Arians. Theodosius then summoned a council to meet at Constantinople in May 381, the Second Œcumenical Council, which reaffirmed the Nicene Creed.
A much larger significance has been given to the Edict of Thessalonica than it possessed, although it was important enough in its time. This is discussed in my blog entry for this date last year, which see.
Occasional comments by a convert to Orthodoxy.