Ptolemy Keraunos

Ptolemy Keraunos (Greek: Πτολεμαῖος Κεραυνός, died 279 BC) was the King of Macedon from 281 BC to 279 BC. His epithet Keraunos is Greek for "Thunder" or "Thunderbolt".

Ptolemy was the eldest son of Ptolemy I Soter, Pharaoh of Egypt, and his second wife Eurydice, daughter of the regent Antipater. After Keraunos' younger half-brother, also called Ptolemy, was named heir apparent and, in 282 BC, ascended to the throne as Ptolemy II, he had to leave Egypt, being a potential rival for the throne. He arrived at the court of Lysimachus, the king of Thrace, Macedon, and part of Asia Minor, where his half-sister Arsinoe was queen.

While Ptolemy was staying in Lysimachus's court, Arsinoe's intrigues led to the accusation of Lysimachus' first son, Agathocles, of treason and to his execution. Keraunos sided with his other sister (from the same mother) Lysandra, who was Agathocles' wife, and accompanied her to the court of Seleucus in the East to solicit his aid. Seeing an opportunity to intervene for his own gain in the politics of both Lysimachan Thrace and Ptolemaic Egypt, Seleucus prepared an expedition against Lysimachus shortly afterwards.

After Lysimachus' defeat and death in the Battle of Corupedium in 281 BC, against Seleucus I Nicator, Ptolemy Keraunos murdered Seleucus I in order to gain the power of his former protector. He then rushed to Lysimacheia where he had himself acclaimed king by the Macedonian army. At this time he also formally relinquished his claim to the Egyptian throne. To stabilize his throne, Ptolemy asked his half-sister Arsinoe, the widow of Lysimachus, to marry him. In 281 BC, he made an alliance with Pyrrhus of Epirus. His only rival, Antigonos Gonatas (Greek : Αντίγονος Γονατάς), son of the ex-king of Macedon, Demetrius I Poliorcetes (Greek : Δημήτριος Πολιορκητής), was confined in the city of Demetrias, Thessaly, and so Keraunos' power extended to south Greece as well.

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