[1] The previous year, the Emperor Theodosius I had appointed the candidate Nectarius as Archbishop of Constantinople.
The bishops of the West opposed the election result and asked for a common synod of East and West to settle the succession of the see of Constantinople, and so the Emperor Theodosius, soon after the close of the First Council of Constantinople in 381, summoned the Imperial bishops to a fresh synod at Constantinople; nearly all of the same bishops who had attended the earlier synod re-assembled in the early summer of 382.
On arrival they received a letter from the synod of Milan, inviting them to a great general council at Rome; they indicated that they must remain where they were, because they had not made any preparations for such long a journey; however, they sent three—Syriacus, Eusebius, and Priscian—with a joint synodal letter to Pope Damasus, Ambrose, archbishop of Milan, and the other bishops assembled in the council at Rome.
[3] The Oxford Dictionary of the Christian Church states:[1] A council probably held at Rome in 382 under St. Damasus gave a complete list of the canonical books of both the Old Testament and the New Testament (also known as the 'Gelasian Decree' because it was reproduced by Gelasius in 495), which is identical with the list given at Trent.The Oxford Dictionary of the Christian Church also notes that "according to E. von Dobschütz, the Gelasian Decree is not a Papal work at all, but a private compilation which was composed in Italy (but not at Rome) in the early 6th century.
It is now commonly held that the part of the Gelasian Decree dealing with the accepted canon of Scripture is an authentic work of the Council of Rome of 382 A.D. and that Gelasius edited it again at the end of the fifth century, adding to it the catalog of the rejected books, the apocrypha.