WORLD HISTORY · TIMELINE 日本語
The 4th century301–400
What were the key events of the 4th century?
In the 4th century (301–400), the Edict of Milan legalized Christianity, Constantinople became the new capital, and the Roman Empire was later divided into eastern and western halves. In China, the north split into the Sixteen Kingdoms while the Eastern Jin was founded in the south, and India flourished under the Gupta Empire.
- Northern China splits into the Sixteen KingdomsAsia
- Edict of Milan legalizes ChristianityEurope
- Western Jin falls; Eastern Jin founded in the southAsia
- Classical Indian culture flourishes under the GuptasAsia
- Council of Nicaea adopts the Nicene CreedMiddle East
- Constantinople becomes the new capitalMiddle East
- Germanic migrations beginEurope
- Roman Empire splits into East and WestEurope
Summaries are written by the site editors.
Key events of the 4th century (timeline · excerpt)
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San Marino, one of the smallest nations in the world and the world's oldest republic still in existence, is founded by Saint Marinus.
Roman emperor Diocletian orders the destruction of the Christian church in Nicomedia, beginning eight years of Diocletianic Persecution.
Sima Chi becomes emperor of the Jin dynasty in succession to his brother, Sima Zhong, despite a challenge from his other brother, Sima Ying.
After divorcing his wife Minervina, Constantine marries Fausta, daughter of the retired Roman emperor Maximian.
At Carnuntum, Emperor emeritus Diocletian confers with Galerius, Augustus of the East, and Maximianus, the recently returned former Augustus of the West, in an attempt to end the civil wars of the Tetrarchy.
Sixty-five days after being exiled by the Emperor Maxentius to Sicily, Pope Eusebius dies.
Constantine the Great enters Rome after his victory at the Battle of the Milvian Bridge, stages a grand adventus in the city, and is met with popular jubilation. Maxentius' body is fished out of the Tiber and beheaded.
Edict of Milan legalizes Christianity
The decisions of the Edict of Milan, signed by Constantine the Great and co-emperor Valerius Licinius, granting religious freedom throughout the Roman Empire, are published in Nicomedia.
The Arch of Constantine is completed near the Colosseum in Rome to commemorate Constantine I's victory over Maxentius at the Milvian Bridge.
Western Jin falls; Eastern Jin founded in the south
Pappus of Alexandria, Greek philosopher, observes an eclipse of the Sun and writes a commentary on The Great Astronomer (Almagest).
Constantine the Great decisively defeats Licinius in the Battle of Chrysopolis, establishing Constantine's sole control over the Roman Empire.
The First Council of Nicaea is formally opened, starting the first ecumenical council of the Christian Church.
The official opening of Constantine's Bridge built over the Danube between Sucidava (Corabia, Romania) and Oescus (Gigen, Bulgaria) by the Roman architect Theophilus Patricius.
Constantine the Great dedicates the much-expanded and rebuilt city of Byzantium, changing its name to New Rome and declaring it the new capital of the Eastern Roman Empire.
Emperor Constantine the Great announces free distributions of food to the citizens in Constantinople.
Roman Emperor Constantine the Great elevates his youngest son Constans to the rank of Caesar.
Athanasius, 20th pope of Alexandria, is banished to Trier on the charge that he prevented a grain fleet from sailing to Constantinople.
Constantine II, Constantius II, and Constans succeed their father Constantine I as co-emperors. The Roman Empire is divided between the three Augusti.
General Magnentius is proclaimed emperor by Roman aristocrats discontent with the rule of emperor Constans.
Vetranio proclaims himself Caesar after being encouraged to do so by Constantina, sister of Constantius II.
The Roman usurper Nepotianus, of the Constantinian dynasty, proclaims himself Roman emperor, entering Rome at the head of a group of gladiators.
Vetranio meets Constantius II at Naissus (Serbia) and is forced to abdicate his imperial title. Constantius allows him to live as a private citizen on a state pension.
Constantius Gallus is elevated as Caesar and then sent to Antioch to govern the Roman East.
Claudius Silvanus, accused of treason, proclaims himself Roman Emperor against Constantius II.
The anti-paganism policy of Constantius II forbids the worship of pagan idols in the Roman Empire.
Emperor Constantius II enters Rome for the first time to celebrate his victory over Magnus Magnentius.
Emperor Constantius II dies of a fever at Mopsuestia in Cilicia; on his deathbed he is baptised and declares his cousin Julian rightful successor.
Roman–Persian Wars: Emperor Julian arrives at Antioch with a Roman expeditionary force (60,000 men) and stays there for nine months to launch a campaign against the Persian Empire.
Roman emperor Julian leaves Antioch with an army of 90,000 to attack the Sasanian Empire, in a campaign which would bring about his own death.
The Roman emperor Julian defeats the Sasanian army in the Battle of Ctesiphon, under the walls of the Sasanian capital, but is unable to take the city.
Roman emperor Julian is fatally wounded by Sassanid troops in a skirmish close to Samarra while retreating from his failed siege of Ctesiphon.
Jovian is proclaimed Roman emperor following the death of emperor Julian in the previous night.
The Crete earthquake occurs with a maximum Mercalli intensity of XI (Extreme), causing a destructive tsunami that affects the coasts of Libya and Egypt, especially Alexandria. Many thousands are killed.
Roman usurper Procopius bribes two legions passing by Constantinople, and proclaims himself emperor.
Gratian, son of Roman Emperor Valentinian I, is named co-Augustus at the age of eight by his father.
Sixteen Kingdoms: Sima Yao, age 10, succeeds his father Emperor Jianwen as Emperor Xiaowu of the Eastern Jin dynasty.
General Siyaj K'ak' conquers Tikal, enlarging the domain of King Spearthrower Owl of Teotihuacán.
Gothic War: Battle of Adrianople: A large Roman army led by Emperor Valens is defeated by the Visigoths. Valens is killed along with over half of his army.
Emperor Gratian elevates Flavius Theodosius at Sirmium to Augustus, and gives him authority over all the eastern provinces of the Roman Empire.
Edict of Thessalonica: Emperor Theodosius I and his co-emperors Gratian and Valentinian II declare their wish that all Roman citizens convert to Nicene Christianity.
The end of the First Council of Christian bishops convened in Constantinople by the Roman emperor Theodosius I.
Roman Emperor Theodosius I concludes a peace treaty with the Goths and settles them in the Balkans.
Roman Emperor Gratian is murdered at a banquet after having surrendered to the forces of rival emperor Magnus Maximus.
Emperor Valentinian II is assassinated while advancing into Gaul against the Frankish usurper Arbogast. He is found hanging in his residence at Vienne.
The Graffito of Esmet-Akhom, the latest known inscription in Egyptian hieroglyphs, is written.
On the first day of the battle of Frigidus, the Western Roman troops of Arbogast manage to defend their positions against the Eastern Roman troops of emperor Theodosius I.
Battle of the Frigidus: Roman emperor Theodosius I defeats and kills Eugenius the usurper. His Frankish magister militum Arbogast escapes but commits suicide two days later.
Roman Empire splits into East and West
Emperor Arcadius marries Aelia Eudoxia, daughter of the Frankish general Flavius Bauto. She becomes one of the more powerful Roman empresses of Late Antiquity.
End of the Gildonic rebellion after Gildo's forces are defeated by forces loyal to Western Roman Emperor Honorius under Gildo's brother Mascezel and Gildo's subsequent death.
Source: Wikipedia date pages ("January 1" … "December 31") / CC BY-SA 4.0. Regions are assigned by the site editors.
Dates and events are based on Wikipedia and other references. Summaries and regions are written by the site editors.