The 4th century BC
started the first day of 400 BC
and ended the last day of 301 BC
. It is considered part of the Classical era
, or historical period
This century marked the height of Classical Greek civilization in all of its aspects. By the year 400 Greek philosophy, art, literature and architecture had spread far and wide, with the numerous independent Greek colonies that had sprung up throughout the lands of the eastern Mediterranean.
Arguably the most important series of political events in this period were the conquests of Alexander, bringing about the collapse of the once formidable Persian Empire and spreading Greek culture far into the east. Alexander dreamed of an east/west union, but when his short life ended, his vast empire was plunged into civil war as his generals each carved out their own separate kingdoms. Thus began the Hellenistic age, a period characterized by a more absolute approach to rule, with Greek kings taking on royal trappings and setting up hereditary successions. While a degree of democracy still existed in some of the remaining independent Greek cities, many scholars see this age as marking the end of classical Greece.
- Mid-4th century BC — Priene, Western Turkey is rebuilt.
- 4th century BC — Pectoral, from the tomb of a Scythian at Ordzhonikidze, Russia, is made. It is now at Historical Museum, Kiev.
- Late 4th century BC — Diadem, reputed to have been found in a tomb near the Hellespont. It is now at The Metropolitan Museum of Art, New York.
- Praxiteles or his followers makes Hermes and the infant Dionysos. A Hellenistic or Roman copy after a Late Classical original is at Archaeological Museum, Olympia. Discovered in the rubble or the ruined Temple of Hera at Olympia in 1875.
- 399 BC Socrates is executed in Athens on charges of impiety and corrupting Athenian youth.
- 383 BC Second Buddhist council at Vesali, 100 years after the Parinirvana.
- 373 BC The Greek city of Helike sinks into the sea causing the death of its entire population.
- c. 360 BC Theater of Tholos, at Epidauros is built.
- Mid-4th century BC — Skopas (?) makes Panel from the Amazon frieze, south side of the Mausoleum at Halikarnassos. It is now kept at The British Museum, London.
- 354 BC, the Battle of Guiling in China.
- 342 BC, the Battle of Maling in China.
- 323 BC Alexander the Great conquers the Persian Empire, decline and depopulation of Ancient Greece with large migrations towards the conquered lands.
- 316 BC The Chinese State of Qin conquers the State of Shu, located in modern-day Sichuan, the ultimate success of the conquest due large in part to the strategy of Zhang Yi.
- 312 BC Seleucus I Nicator establishes himself in Babylon, founding the Seleucid Empire.
- Invasion of the Celts into Ireland.
- Battle of the Allia and subsequent Gaulish sack of Rome.
- The Scythians are beginning to be absorbed into the Sarmatian people.
- The Romans conquer the Abruzzi region, decline of the Etruscan civilization.
- Marcus Furius Camillus, Roman dictator (c. 446–365 BC)
- Plato, philosopher (c. 427–347 BC)
- Tollund Man, Human sacrifice victim on the Jutland Peninsula in Denmark, possibly the earliest known evidence for worship of Odin
- Aristotle, philosopher and scientist (384–322 BC)
- Philip II of Macedonia (born 382, reigned 359–336 BC)
- Demosthenes (384–322 BC), a prominent Athenian statesman and orator, who became a fierce opponent of Philip II and Alexander of Macedon
- Gan De, Chinese astronomer
- Shi Shen, Chinese astronomer
- Darius III of Persia, last King of the Achaemenid dynasty (born 380, reigned 359–330 BC)
- Mencius, Chinese philosopher and sage (371–289 BC)
- Yang Zhu (also Yang Chu), Chinese philosopher for egoism and intellectual rival of Mencius (370–319 BCE)
- Ptolemy I Soter, founder of the Ptolemaic dynasty (c. 367–283 BC)
- Shang Yang, Prime Minister of Qin, his reform helped Qin to become the strongest country and later unified China (term 361–338 BC)
- Seleucus I Nicator, founder of the Seleucid Empire (c. 358–281 BC)
- Alexander the Great, King of Macedon, invades Asia Minor, Persia and reaches India (born 356, reigned 336–323 BC)
- Brennus, Gaulish chieftain
- Zhuangzi, Chinese philosopher
- Archon of Pella, Babylonian satrap
- Sun Bin, Chinese general and military strategist (d. 316 BC)
Inventions, discoveries, introductions
- Oldest Brahmi script dates from this period (Brahmi is the ancestor of Indic scripts).
- Romans build first aqueduct.
- Chinese use the handheld trigger crossbow for the first time.
- The first crossbow, the gastraphetes, is invented at Syracuse.
- Burnt brick first used in Greece.
- Donkey-powered mills first used in Greece.
- Torque with lion's-head terminals, from Susa (modern Shush, Iran) was made. It is now in Musee du Louvre, Paris.
- Daric, a coin first minted under Darius I of Persia was made. It is now in Heberden Coin room, Ashmolean Museum, Oxford.
- Starting in the year 309 BC, the later Chinese historian Sima Qian (145 BC–90 BC) wrote that the Qin-employed engineer Bi Ling of the newly conquered State of Shu in Sichuan had the shoulder of a mountain cut through, making the 'Separated Hill' that abated the Mo River, and excavated two canals in the plain of Chengdu. The significance of this was phenomenal, as it allowed the new Guanxian irrigation system to populate an area of some 40 by 50 miles (60 × 80 km) with over five million people, still in use today (Needham, Science and Civilization in China, Volume 4, Part 3, 288).
- The Chinese astronomer Gan De divides the celestial sphere into 365¼ degrees, and the tropical year into 365¼ days at a time when most astronomers used the Babylon division of the celestial sphere as 360 degrees (Deng, Yinke.  (2005). Chinese Ancient Inventions. ISBN 7508508378).
Decades and years