Below are some of the important events that happened between 380 and 389.
- January or February – Emperor Theodosius I is baptized.
- February 27 – Edict of Thessalonica: Theodosius I, with co-emperors Gratian and Valentinian II, say that all Roman citizens should become Christians.
- The Rock of Cashel is built in Ireland.
- The Visigothic chieftain Fritigern dies. His rival Athanaric becomes king of the entire Gothic nation.
- Roman Emperor Gratian moves the capital to Mediolanum (modern Milan).
- The Visigothic chieftain Athanaric becomes the first foreign king to visit the East Roman capital of Constantinople.
- Flavian succeeds Meletius as Patriarch of Antioch.
- Timothy succeeds Peter as Patriarch of Alexandria.
Births
- Helian Bobo, emperor of the Chinese Xiongnu state Xia
- Roman Emperor Gratian removes the Altar of Victory from the Senate.
Births
- Jin Andi, emperor of the Eastern Jin Dynasty
- Sima Yuanxian, regent during the Jin Dynasty
- Niall of the Nine Hostages becomes the first High King of Ireland.
- Hadrian's Wall is overrun by the Picts.
- January 19 – Arcadius becomes Roman Emperor.
- Roman troops in Britain call Magnus Maximus Emperor. He crosses over to the continent and makes Trier his capital.
- King Ardashir II dies after a 4-year reign. He is succeeded by his son Shapur III.
Births
- September 9 – Honorius, Roman Emperor
- Chu Lingyuan, last empress of the Jin Dynasty
- Maria, empress and daughter of Stilicho
- Sengzhao, Chinese Buddhist
- Wang Shen'ai, empress of the Jin Dynasty
Deaths
- December 11 – Pope Damasus I
- Chu Suanzi, empress of the Jin Dynasty
- Geungusu, king of Baekje
- Murong Hong, founder of the Xianbei state Western Yan
- Jinsa of Baekje becomes the 16th king of the ancient Korean kingdom of Baekje.
- Copper extraction and casting begins in the mines of Kansanshi in southernmost Africa.
- Ammianus Marcellinus begins writing a history covering the years 96 to 378.
- The Serapeum in Alexandria is destroyed.
- Aurelios Zopyros becomes the last reported athlete at the Ancient Olympic Games.
Deaths
- Aelia Flaccilla, Roman empress and wife of Theodosius I
- Chimnyu, king of Baekje (Korea)
- Dao An, Buddhist monk of the Jin Dynasty
- Fú Jiān, emperor of the Chinese Di state Former Qin
- Murong Wei, emperor of the Xianbei state Former Yan
- The Greuthungi cross the Danube to raid the Roman garrisons.
- Magnus Maximus invades Italy.
- The Northern Wei Dynasty begins in China.
Deaths
- Cyril of Jerusalem, theologian and saint
- Duan Sui, ruler of the Western Yan
- Fu Pi, emperor of the Former Qin
- Jin Feidi, emperor of the Jin Dynasty
- Murong Chong, emperor of the Western Yan
- Murong Yao, emperor of the Western Yan
- Murong Yi, ruler of the Western Yan
- Murong Zhong, emperor of the Western Yan
Births
- Yao Hong, emperor of the Chinese Qiang state Later Qin
Deaths
- Flavius Victor, son of Magnus Maximus and co-emperor
- Qifu Guoren, ruler of the Xianbei state Western Qin
- Shapur III, king of the Sassanid Empire
Births
- Geiseric, king of the Vandals and Alans
Deaths
- Mao, Chinese empress and wife of Fu Deng
- January 25 – Gregory Nazianzus, theologian