294 BC

By place

Greece

• Archidamus IV, king of Sparta, son of Eudamidas I and grandson of Archidamus III, is defeated by Demetrius Poliorcetes of Macedonia in a battle at Mantinea. Sparta is saved only because Demetrius is called away by the threatening activities of his rivals Lysimachus and Ptolemy.
• Alexander V of Macedon is ousted by his brother, Antipater II. Therefore Alexander V turns to Demetrius Poliorcetes for help in recovering his throne. However, Demetrius Poliorcetes establishes himself on the throne of Macedonia and then murders Alexander V. Antipater II loses the throne of Macedonia but is able to survive.
• Pyrrhus of Epirus exploits the dynastic quarrel in Macedonia involving Alexander V of Macedon, his brother, Antipater II and Demetrius Poliorcetes to take over the frontier areas of Parauaea and Tymphaea, along with Acarnania, Ampholochia, and Ambracia.
• Lysimachus concludes a peace with Demetrius Poliorcetes whereby Demetrius Poliorcetes is recognized as ruler of Macedonia.

  Egypt

• Ptolemy gains control over Cyprus and the Phoenician coastal towns of Tyre and Sidon.

  Seleucid Empire

• Stratonice, daughter of Demetrius Poliorcetes and wife of Seleucus marries her stepson Antiochus. Seleucus has reportedly instigated the marriage after discovering that his son by his late wife Apama was in danger of dying of lovesickness as he has fallen in love with his beautiful stepmother.