320 BCE

Theophrastus begins the systematic study of botany. Eudemus makes himself master of the territories of the Indian king Porus, and treacherously puts that monarch to death. Alexandria in Macedonian Egypt becomes the largest city of the world, taking over the lead from Babylon in Macedonian Babylonia.

Geopolitics & Diplomacy

Judea and Syria are annexed by Ptolemy and he gives Judea a large measure of self-government.source

Conflict & Security

Alexander the Great's various generals control different parts of Alexander's empire. Ptolemy controls Egypt, Seleucus controls Babylon and Syria, Antipater and his son Cassander control Macedon and Greece, Antigonus controls Phrygia and other parts of Asia Minor, Lysimachus controls Thrace and Pergamum and Eumenes controls the Cappadocia and Pontus areas.source
Eudemus makes himself master of the territories of the Indian king Porus, and treacherously puts that monarch to death.source
Alexandria in Macedonian Egypt becomes the largest city of the world, taking over the lead from Babylon in Macedonian Babylonia.source

Science & Discovery

Theophrastus begins the systematic study of botany.source

Births

Timocharis of Alexandria, Greek astronomer responsible for the first recorded observation of Mercury and the first star catalogue (d. 260 BC)source
Bindusara, the heir to the throne of the Mauryan Empire, is born. (d. 272 BC)source

Deaths

Zoilus, Greek grammarian, cynic philosopher and literary critic from Amphipolis in Macedon (b. c. 400 BC)source
Menaechmus, Greek mathematician and geometersource
Anaximenes of Lampsacus, Greek rhetorician and historian (b. c. 380 BC)source