282 BC

By place

Asia Minor

• The city of Pergamum in Asia Minor ends its allegiance to Lysimachus. Its ruler, Philetaerus, transfers his allegiance, as well as the important fortress of Pergamon and his treasury, to Seleucus, who allows him a far larger measure of independence than he had hitherto enjoyed.

  Roman Republic

• The Battle of Populonia is fought between Rome and the Etruscans. The Romans are victorious and, as a result, the Etruscan threat to Rome is sharply diminished.
• The Magna Graecia city of Thurii appeals to Rome for help against the native Italian tribes. Though the Roman Senate hesitates, the plebeian Assembly decides to respond. Thurii is saved, but Tarentum, jealous of Rome's interference, attacks and sinks some Roman ships entering its harbour. Roman envoys, sent to protest, are mistreated.
• Rome declares war on Tarentum. King Pyrrhus of Epirus declares his willingness to come to the aid of Tarentum. Tarentum also looks for support from the Samnites and other Italian tribes in southern Italy.

  Egypt

• Arsinoe, daughter of Lysimachus, king of Thrace, marries Ptolemy II of Egypt as part of the alliance between Thrace and Egypt against Seleucus.