Exploration & Expansion in the 4th century

37 sourced entries, 300 CE to 399 CE, oldest first. Also see Exploration & Expansion across every century or everything else in the 4th century.

• 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.source
• 300The magnetic compass for navigation is invented in China (approximate date).source
• 305Maximian retires from office, and leaves for Campania or Lucania (southern Italy), to live a life of ease in his luxury villas.source
• 307Summer: Anticipating an offensive by Galerius, Maximian travels to Gaul to make an alliance with Constantine I.source
• 315Constantine the Great and co-emperor Licinius battle the Sarmates, the Goths and the Carpians along the Danube. Constantine leads a punitive expedition into Dacia and reestablishes the Roman fortifications of the frontier.source
• 320King Chandragupta I founds the Gupta dynasty in northern India (approximate date).source
• 320In Nydam Mose (Denmark), the Nydam oak boat is sacrificed by the Danes (the boat is excavated in the 1830s, when a local farmer finds weapons, including swords and spears).source
• 321Emperor Constantine I expels the Goths from the Danube frontier and repairs Trajan's Bridge. He leads an expedition into the old province Dacia (modern Romania) and makes peace with the barbarians.source
• 321History of the Jews in Germany: Jews in modern-day Germany are documented for the first time, in Colonia Agrippinensium (modern-day Cologne).source
• 327Emperor Constantine the Great decrees that rural slaves can only be sold in the province where they reside, in order to resolve the shortage of labour in the Roman Empire.source
• 331Gregory the Illuminator withdraws to a small sanctuary in the Daranali province (Armenia).source
• 345Merchant Knai Thomman and 400 followers visit the Malabar Coast in Kerala (India), and assist the church there.source
• 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).source
• 355The Huns of Central Asia begin their great drive westwards with an advance into Scythia (modern Ukraine). They overcome and absorb the Alans, a nomadic and warlike horse breeding people from the steppes northeast of the Black Sea.source
• 362Julian builds a fleet of 50 warships, and more than 1,000 transport boats at Samosata, for his expedition in Persia against King Shapur II the Great.source
• 363April – Julian crosses the Euphrates near Hierapolis, using 50 pontoon ships, and moves eastwards to Carrhae. He destroys Perisapora and overruns Persian forts along the desert frontier (Limes Arabicus).source
• 363The Huns first appear in Europe and reach the Caspian Sea.source
• 366January 31 – Athanasius of Alexandria returns from his fifth exile. He has spent four months in his ancestral tomb outside Alexandria.source
• 366Buddhist monk Lè Zūn has a vision of "golden rays of light shining down on 1,000 Buddhas", resulting in the creation of the Mogao Caves.source
• 368Winter – The barbarians are driven back to their homelands, Hadrian's Wall is retaken and order returns to the Roman diocese. Theodosius reorganises the abandoned forts and mounts punitive expeditions in Hibernia (Ireland).source
• 369Eastern Jin general Huan Wen's third northern expedition is defeated by Former Yan general Murong Chui.source
• 370Athanaric, Gothic leader of the Tervingi, advances eastwards and takes up a defensive position along the banks of the Dniester (Romania).source
• 371Roman poet Ausonius writes of a voyage on the Rhine and the Moselle in his work 'Mosella'.source
• 373Count Theodosius the Elder is appointed commander of an expedition to suppress the rebellion of Firmus in Mauretania.source
• 374The Quadi cross the Danube and begin ravaging Pannonia. They avoid the fortified cities and plunder the unprotected countryside.source
• 375The earliest extant books – a school textbook and an account book – with bound wooden leaves, are lost at the Dakhla Oasis in western Egypt. The desert sands preserve them for modern archaeologists.source
• 375Saint Jerome retires to the desert of Chalcis (Syria).source
• 377The Goths (possibly Greuthungi) make an alliance with some of the Huns and Alans along the Danube, and entice them across the river. With the balance of power now shifted Saturninus concentrates his forces to avoid his outposts being overrun. This opens the passes, allowing the Goths, Huns and Alans to break out into the lowlands of southern Thrace.source
• 377The Goths, now seeking a military victory to force the Empire to make terms, aim to dislodge the army of Frigeridus from Beroea. He withdraws over the Succi (Ihtiman) Pass back to Illyrium, and reports to Gratian that an expedition by the main imperial armies is required to repulse the Goths in Thrace.source
• 378Roman reconnaissance detects the Goths. Valens, already west of Adrianople, turns back and establishes a fortified camp outside the city.source
• 378Gratian sets out from Lauriacum (Austria) with a body of light armed troops. His force is small enough to travel by boat down the Danube. He halts for four days at Sirmium (Serbia) suffering from fever.source
• 378Fritigern concentrates his army at Cabyle (Bulgaria). The Goths are mainly centred in the river valleys south of the Balkan Mountains, around the towns of Beroea, Cabyle and Dibaltum.source
• 380The annexation of western provinces by Chandragupta II gives him commerce with Europe and Egypt.source
• 380Easter Island, in the south Pacific Ocean, has been occupied by Neolithic seafarers under Hotu Matu'a ("supreme chief"), who about this time begin to fortify the island.source
• 388Jerome moves to Palestine, where he spends the rest of his life as a hermit near Bethlehem.source
• 397The Xiongnu occupy the Gansu area, an economically important province situated along the Silk Road.source
• 399Fa-Hien, Chinese Buddhist monk, travels to India, Sri Lanka and Kapilavastu (modern Nepal).source