The 330s decade ran from January 1, 330, to December 31, 339.
- May 11 – Emperor Constantine the Great dedicates the Column of Constantine and Constantinople, or Nova Roma (modern Istanbul). He had spent 4 years expanding the city of Byzantium, having chosen the site for its strategic location on the Bosporus. The city is later the capital of the Eastern Roman Empire.
- The Goths devastate the city of Tanais, in the Don River Delta.
- Ezana, king of Axum, extends his area of control to the west. He defeats the Nobates, and destroys the kingdom of Meroë.
- Frumentius is the first bishop of Ethiopia (approximate date).
- Eustathius, Patriarch of Antioch, is banished to Trajanopolis.
- The Bible is translated into the Gothic language by Wulfila.
- Pagan temples begin to be progressively abandoned, destroyed or left to fall into disrepair, save those that are transformed into churches.
- Emperor Constantine the Great vigorously promotes Christianity, confiscating the property and valuables of a number of pagan temples throughout the Roman Empire.
- Constantine I dedicates the Church of the Holy Apostles in Constantinople.
- Constantine I promulgates a law against divorce.
Arts and sciencesEdit
- Eusebius of Caesarea writes the Onomasticon.
- Emperor Constantine I and his son Constantine II, aged 16, defeat the Goths in Moesia. The Goths become Roman allies and protect the Danube frontier.
- Constantine I continues construction of a bridge in imitation of Trajan and his architect Apollodorus of Damascus across the Danube for forward-staging grounds for planned campaigns against local tribes.
- May 18 – Constantine I announces a free distribution of food to the citizens in Constantinople, similar to the food given out in the city of Rome. The amount is approximately 80,000 rations a day, doled out from 117 distribution points around the city.
- Flavius Dalmatius and Domitius Zenofilus are appointed consuls.
- Emperor Constantine the Great pulls Roman troops out of Britain, and abandons work on Hadrian's Wall.
- Calocaerus revolts against Constantine I and proclaims himself emperor. Flavius Dalmatius, responsible for the security of the eastern frontier, is sent to Cyprus to suppress the rebellion.
- December 25 – Constantine I elevates his youngest son Constans to the rank of Caesar at Constantinople.
- Shi Hong succeeds his father Shi Le as Emperor of the Later Zhao Empire, in the Period of the Sixteen Kingdoms, but Shi Hong's third cousin Shi Hu holds the real power. Empress Dowager Liu (widow of Shi Le) fails to get rid of Shi Hu, and Shi Hu has her deposed and killed.
- Flavius Dalmatius puts down a revolt in Cyprus led by Calocaerus. Calocaerus is brought to Tarsus (Cilicia) and executed.
- The Goths protect the Danube frontier against an invasion by the Vandals.
- Emperor Constantine the Great reauthorises gladiatorial combat.
- Julius Firmicus Maternus makes the first recorded observation of solar prominences, during an annular eclipse (July 17).
- September 14 – Emperor Constantine I consecrates the Church of the Holy Sepulchre in Jerusalem.
- September 19 – Flavius Dalmatius is raised to the rank of Caesar, with control of Thracia and Macedonia.
- Hannibalianus, nephew of Constantine I, is made Rex Regum ("King of Kings of the Pontic people").
- November 7 – Athanasius is banished to Trier, on the charge that he prevented the corn fleet from sailing to Constantinople.
- Samudragupta succeeds Chandragupta I as king of the Gupta Empire.
- Tuoba Hena ousts Tuoba Yihuai as chieftain of the Tuoba Clan.
- Emperor Shi Hu moves the capital of the Later Zhao state to Yecheng.
- First Synod of Tyre: Constantine I convenes a gathering of bishops at Tyre to depose and exile Patriarch Athanasius of Alexandria.
- Constantine I reinstates the Alexandrian priest Arius (declared a heretic at the First Council of Nicaea in 325) in a synod at Jerusalem about a year before Arius' death.
- September 13 – The Church of the Holy Sepulchre in Jerusalem is consecrated.
- December 31 – Pope Sylvester I dies at Rome after a 21-year reign. He is succeeded by Mark as the 34th pope.
- The military successes of Emperor Constantine I result in most of Dacia being reconquered by the Roman Empire.
- The first recorded customs tariff is in use in Palmyra.
- January 18 – Pope Mark succeeds Pope Sylvester I as the 34th pope.
- Pope Mark begins to build the basilica of San Marco; the church is devoted to St. Mark.
- Arius, Alexandrian priest, collapses in the street at Constantinople (approximate date).
- Pope Mark dies at Rome after an 11-month reign. No successor is immediately found.
- Emperor Constantine blends Pagan and Christian rites to create Christmas, and sets the date of Jesus' birth as December 25th.
- May 22 – Constantine the Great, first Christian Roman emperor of the Western Empire (312–324), and of the Roman Empire (324–337), dies in Achyron, near Nicomedia, at age 65 after he is baptized by Eusebius of Nicomedia.
- September – A number of descendants of Constantius Chlorus, and officials of the Roman Empire, are executed for a purge against the sons of Constantine I.
- September 9 – Constantine II, Constantius II, and Constans succeed their father Constantine I as co-emperors. The Roman Empire is divided between the three Augusti (see map).
- King Shapur II of Persia begins a war against the Roman Empire. He sends his troops across the Tigris to recover Armenia and Mesopotamia.
- Shapur II besieges the Roman fortress of Nisibis (Syria), but is repulsed by the forces under Lucilianus.
- February 6 – A 4-month papal vacancy ends. Pope Julius I succeeds Pope Mark as the 35th pope.
- June 17 – Constantius II announces the restoration of Athanasius as Patriarch of Alexandria.
- Paul I becomes Patriarch of Constantinople.
- Christianity is declared an official religion in Caucasian Iberia, marking the rise of Christianity in Georgia.
- The Romans, allied with the Goths, arrive in the north of the Roman Empire to protect the Danube frontier.
- Emperor Constantius II intervenes against the Persians in Armenia.
- Shapur II, king of the Persian Empire, begins a widespread persecution of Christians; he orders forcible conversions to the state religion, Zoroastrianism, lest the Christians disrupt his realm while he is away fighting the Romans in Armenia and Mesopotamia.
- Eusebius of Nicomedia becomes Patriarch of Constantinople after Paul I is banished.
- Non-Christians are persecuted by the Roman Empire as pagans.
- Emperor Constantius II hastens to his territory in the East, where a revived Persia under King Shapur II is attacking Mesopotamia. For the next 11 years, the two powers engage in a war of border skirmishing, with no real victor.
- Basil the Great, bishop of Caesarea Mazaca (d. 379)
- Macrina the Younger, Christian nun and saint (d. 379)
- Moses the Black, Christian monk and priest (d. 405)
- Victricius, missionary and bishop of Rouen (approximate date)
- Jovian, Roman Emperor (d. 364)
- Julian the Apostate, Roman Emperor (d. 363)
- Yao Chang, emperor of the Qiang state Later Qin (d. 394)
- Huiyuan, Chinese Buddhist teacher and founder of the Donglin Temple (d. 416)
- Sabbas the Goth, Christian reader and saint (d. 372)
- Virius Nicomachus Flavianus, Roman historian and politician (d. 394)
- Fu Sheng, emperor of the Chinese Di state Former Qin (d. 357)
- Gregory of Nyssa, Christian bishop and saint (approximate date)
- Magnus Maximus, Western Roman Emperor (approximate date)
- Theon of Alexandria, last director of the Library of Alexandria (approximate date)
- Murong De, emperor of the Xianbei state Southern Yan (d. 405)
- Richū, emperor of Japan (approximate date)
- Faxian, Chinese Buddhist monk and traveler (approximate date)
- Fú Jiān, emperor of the Chinese Di state Former Qin (d. 385)
- Lü Guang, founding emperor of the Di state Later Liang (d. 400)
- Zenobius of Florence (d. 417)
- May 15 – Achillius of Larissa, Greek saint
- June 30 – Tiridates III, king of Arsacid Armenia, Armenian Orthodox priest and saint
- August 18 – Helena, Empress of the Roman Empire and Roman Catholic religious sister and saint (b. 250)
- August 28 – Saint Vicinius of Sarsina, first bishop of Sarsina
- Gregory the Illuminator, patron saint and first official head of the Armenian Apostolic Church
- Micheon of Goguryeo, 15th ruler of Goguryeo
- Empress Liu
- Murong Hui, Xianbei chief and Duke Xiang of Liaodong (b. 269)
- Shi Le, founder and emperor of the Chinese Jie state (b. 274)
- December 5 – Li Ban, emperor of Chang Han (b. 288)
- Calocaerus, Roman usurper
- Empress Dowager Cheng
- Li Xiong, first emperor of Cheng Han (b. 274)
- Shi Hong, emperor of the Chinese Jie state (b. 313)
- Tao Kan, general of the Jin Dynasty (b. 259)
- Wei Huacun, founder of the Shangqing sect of Daoism (b. 252)
- December 31 – Pope Sylvester I
- Chandragupta I, king of the Gupta Empire
- Lady Xun, concubine of Emperor Yuan of Jin and mother of Emperor Ming of Jin
- January 13 – Leontius of Caesarea, Roman Catholic bishop and saint
- February 21 – Eustathius of Antioch
- May 22 – Constantine the Great, Emperor of the Roman Empire and Orthodox priest and saint (b. 272)
- May 27 – Flavius Dalmatius, father of Dalmatius and Hannibalianus (executed)
- August 30 – Alexander of Constantinople
- September 11 – Julius Constantius, son of Constantius Chlorus (executed)
- September 24 – Hannibalianus, king of the Pontus and nephew of Constantine I (executed)
- September 27 – Dalmatius, Caesar and nephew of Constantine I (executed)
- Flavius Ablabius, Roman consul and politician
- Li Qi, emperor of the Ba-Di state Cheng Han (b. 314)
- Tuoba Yihuai, prince of the Tuoba Dai clan
- Abaye, Babylonian amora
- Eusebius of Caesarea, bishop and first church historian (approximate date)
- Shemon Bar Sabbae, bishop of Seleucia-Ctesiphon
- Wang Dao, statesman of the Jin Dynasty (b. 276)
- "List of Rulers of Korea". metmuseum.org. Retrieved 19 April 2019.
- Primary source: Themistius, Oration 10.136/206; discussed in Ilkka Syvänne, Military History of Late Rome, 284–361 (Barnsley, South Yorkshire: Pen and Sword, 2015), 73. ISBN 9781473871830
- A.H.M. Jones, The Decline of the Ancient World (London: Routledge, 2014), 49-50. ISBN 9781317873051
- Pohlsander, Hans A. (2004). The Emperor Constantine (2nd ed.). Routledge. p. 78. ISBN 978-0-415-31938-6.
- Kraitser, Charles V. (1837). The Poles in the United States of America. Kiderlen and Stollmeyer. p. 17.
- Townsend, George Henry (1862). The Manual of Dates (2nd ed.). Routledge, Warne & Routledge. p. 757.
- "Chronology of Discoveries About the Sun". MrEclipse.com. 1999. Retrieved 2012-07-03.
- World History of the Customs and Tariffs. World Customs Organization. 2003-01-01. ISBN 9782874920219.
- Zürcher, Erik (1959). The Buddhist conquest of China. 1. Brill Archive. p. 16.
- Hodgkin, Thomas (1892). Italy and Her Invaders. 1 (2nd ed.). Clarendon Press. p. 178.
- Adkins, Lesley; Adkins, Roy A. (2004). Handbook to life in ancient Rome (2nd ed.). Infobase Publishing. p. 17. ISBN 978-0-8160-5026-0.
- Mutschler, Fritz-Heiner; Mittag, Achim (2008). Conceiving the empire: China and Rome compared. Oxford University Press. p. 397. ISBN 978-0-19-921464-8.
- Frédéric, Louis (1977). Encyclopaedia of Asian civilizations. 3. p. 178.
- Pearce, Scott (2001). Spiro, Audrey G.; Ebrey, Patricia Buckley (eds.). Culture and Power in the Reconstitution of the Chinese Realm, 200–600. Harvard Univ Asia Center. p. 76. ISBN 978-0-674-00523-5.
- Liu, Cheng-Tsai; Zheng-Cai, Liu; Hua, Ka (1999). A Study of Daoist Acupuncture. Blue Poppy Enterprises, Inc. p. 17. ISBN 978-1-891845-08-6.