The 4th century
1,525 sourced entries across 100 documented years, grouped into 10 decades. A century here runs 1900–1999 rather than 1901–2000, so its decades sit inside it exactly; on the BC side the same rule puts 1–99 BC in the 1st century BC and 100 BC in the 2nd.
Decades
- The 300s — 10 years, 177 entries
- The 310s — 10 years, 143 entries
- The 320s — 10 years, 117 entries
- The 330s — 10 years, 139 entries
- The 340s — 10 years, 123 entries
- The 350s — 10 years, 150 entries
- The 360s — 10 years, 170 entries
- The 370s — 10 years, 178 entries
- The 380s — 10 years, 181 entries
- The 390s — 10 years, 147 entries
By subject
- Religion & Belief in the 4th century — 243 entries
- Conflict & Security in the 4th century — 231 entries
- Geopolitics & Diplomacy in the 4th century — 71 entries
- Culture & Society in the 4th century — 49 entries
- Exploration & Expansion in the 4th century — 29 entries
- Climate & Environment in the 4th century — 17 entries
- Technology & Infrastructure in the 4th century — 15 entries
- Crime & Justice in the 4th century — 13 entries
- Science & Discovery in the 4th century — 13 entries
- Health & Medicine in the 4th century — 12 entries
A few of the years
- 300The Mayan civilization reaches its most prolific period, the classic period, in what is now Guatemala, Belize and parts of southern Mexico adjacent to the former two. During most of this period, Tikal dominates the Mayan world.
- 312October 28 – Battle of the Milvian Bridge: Constantine defeats Maxentius at the Milvian Bridge, becoming the only Roman emperor in the West. Prior to the battle, he reportedly has a vision of a cross (labarum) with the phrase "in hoc signo vinces" ("In this sign you shall conquer"). This encourages him to convert to Christianity.
- 324July 3 – Battle of Adrianople: Emperor Constantine the Great defeats his rival Licinius near Adrianople, forcing him to retreat to Byzantium. Constantine then invades Thrace with a Visigothic force and raids the countryside.
- 336January 18 – Pope Mark succeeds Pope Sylvester I as the 34th pope of the Catholic Church.
- 348Wulfila escapes religious persecution by the Gothic chieftain Athanaric, obtains permission from Constantius II to migrate with his flock of converts to Moesia, and settles near Nicopolis ad Istrum (Bulgaria).
- 36014 February – The first Hagia Sophia church is consecrated in Constantinople.
- 372September 12 – Jin Xiaowudi, age 10, succeeds his father Jin Jianwendi. Empress Chu Suanzi serves as regent, but decisions are made by the high officials Xie An and Wang Tanzhi.
- 384December 17 – Pope Siricius succeeds Damasus I as the 38th pope. He takes the title Pontifex Maximus, after it is relinquished by the late emperor Gratian.