340s

Millennium:	1st millennium
Centuries:	3rd century – 4th century – 5th century
Decades:	310s 320s 330s – 340s – 350s 360s 370s
Years:	340 341 342 343 344 345 346 347 348 349
340s-related categories:	Births – Deaths – By country Establishments – Disestablishments

This is a list of events occurring in the 340s, ordered by year.

By place

Roman Empire

• Constantinople, capital of Emperor Constantius II, becomes the largest city in the world, taking the lead from Rome, capital of his brother Constans I.
• The Roman emperor of the central part of the Roman empire Constantine II, ruling over the upper Danube, Italy and middle Africa, crosses the Alps and against the army of his brother Constans I, emperor of the western part of the Roman Empire: Britain, Gaul, the Rhine provinces and Iberia. They clash at Aquileia in northern Italy. Constantine is killed in a skirmish by an ambush of Constans troops.
• Constans is left sole ruler of the Western Roman Empire, with his other brother, Constantius II, Emperor of the Eastern Roman Empire.

By topic

Religion

• Pope Julius I inveighs against Arianism at the Council of Rome.
• Acacius succeeds Eusebius as bishop in the see of Caesarea.
• Wulfila spreads evangelism among the Goths for 7 years.

By place

Roman Empire

• Emperor Constans I bans pagan sacrifices and magic rituals under penalty of death.
• Constans I begins a successful campaign against the Franks.

India

• Samudragupta, ruler of the Gupta Empire, extends during a decade his kingdom and his influence over most of India. A pillar found at Allahabad sings his praises.

By topic

Religion

• The Council of Encaenia is held in Antioch.
• Paul I is restored as Patriarch of Constantinople.
• Thousands of Christians are executed at Seleucia in Mesopotamia.
• Coptic Christianity is introduced into Ethiopia by the Syrian apostle Frumentius. He and his colleague Edesius were captured by Ethiopians a year or two ago, and have become civil servants at the Aksumite court of King Ezana. Frumentius becomes the first Bishop of Axum and encouraged the Christian merchants present in the country to practise their faith openly.

By place

Roman Empire

• The Western Roman Emperor Constans campaigns in Britain against the Picts.
• The senate abolishes gay marriage.

Europe

• A large earthquake strikes Cyprus.

Asia

• Goguryeo is invaded by Murong Huang of the Xianbei.
• Jin Kangdi succeeds his brother Jin Chengdi as emperor of China.

By topic

Religion

• Paul I, Patriarch of Constantinople, is deposed and replaced by Macedonius I.
• February 15 – The original Hagia Sophia is dedicated in Constantinople.

By place

Roman Empire

• The Western Roman Emperor Constans I is in Britain, possibly in a military campaign against the Picts and Scots.
• The Eastern Roman Emperor Constantius II campaigns in Adiabene, a vassal kingdom of Armenia (Persian Empire).

By topic

Religion

• Pope Julius I tries to unite the Western bishops against Arianism by convoking the Council of Sardica (later Sofia), which acknowledges the pope's supreme authority and grants him the right to judge cases involving the legal possession of episcopal sees, but only Western and Egyptian bishops attend, and Arianism remains strong.

By place

Roman Empire

• The Eastern Roman Emperor Constantius II campaigns in eastern Mesopotamia against the Sassanid Persians
• Battle of Singara: The Roman army under Constantius wins a close victory at the strongly fortified city of Singara (Mesopotamia). His enemy, King Shapur II is forced to lift the siege and withdraw the Persian army.
• Shapur II besiege for the second time the Roman fortress of Nisibis in eastern Mesopotamia, but is repulsed by forces under the general Lucilianus.

China

• Jin Mudi, age 1, succeeds his father Jin Kangdi as emperor of China. His mother Empress Dowager Chu, becomes the ruling authority at court and served as regent.

By topic

Art

• The making of a detail of Admonitions of the Imperial Instructress to Court Ladies (attributed to Gu Kaizhi and being from the Six Dynasties period) begins (approximate year) and is completed in 406. It is now kept at the British Museum, London.

Religion

• Bishop Eustorgius I brings relics of the Three Magi from Constantinople to Milan, according to a 12th century legend.

By place

India

• The merchant Knai Thomman visits the Malabar Coast in Kerala (India) and assists the church there.

By place

Asia

• In Korea, the Buyeo Kingdom is absorbed by Goguryeo.

By topic

Religion

• Emperor Constans I uses his influence to secure the return of Athanasius. He is restored as Patriarch of Alexandria, and compile documents relating to his expulsion under the title Apology Against the Arians.
• Macedonius I, Patriarch of Constantinople, is deposed again by Paul I.
• Julius Firmicus Maternus writes De erroribus profanarum religionum.
• The Visigoths are converted to Arianism by Wulfila.

By topic

Religion

• Council of Sardica: An attempt is made to resolve the Arian controversy, and ground rules for bishops are laid down.
• The Council of Philippopolis is held as the result of Eastern bishops leaving the Council of Sardica. In Philippopolis (Bulgaria), they excommunicate Pope Julius, and as a result, the Arian controversy is perpetuated.

By place

Europe

• Wulfila escapes religious persecution by the Gothic chieftain Athanaric and obtains permission from Constantius II to migrate with his flock of converts to Moesia and settled near Nicopolis ad Istrum (Bulgaria).

Asia

• In Persia, women are enrolled in the army to perform auxiliary services.
• In India, Samudragupta of the Gupta Empire defeats Rudrasena in battle.

By place

Asia

• Emperor Shi Zun dies after a brief reign of 183 days, he and his mother Empress Zheng Yingtao are executed. His son Shi Jian succeeds him as emperor of the Jie state Later Zhao.
• The Mou-jong (proto-Mongols) take control of North China.

Significant people

• Constans, Roman Emperor
• Constantius II, Roman Emperor
• Flavius Philippus, praetorian prefect of the East, consul
• Hypatia of Alexandria