880

Events 
 Oldest known mention of the city of Dortmund
 Pope John VIII issued the Bill "Industriae Tuae", creating an independent ecclesiastical province in Great Moravia with Archbishop Saint Methodius as its head. The Old Church Slavonic was recognized as the fourth liturgical language, besides Latin, Greek and Hebrew.
Bishopric established in Nitro.

Births
 Fujiwara no Tadahira, Japanese regent
 Louis the Blind, King of Provence (r. 887 – 900), King of Italy (r. 900 – 901), and Holy Roman Emperor (r. 901 – 905)

Deaths
Carloman, King of Bavaria
Emperor Seiwa of Japan