He was the eldest son of Ptolemy I Soter, ruler of Egypt, and his second wife Eurydice, daughter of the regent Antipater. His younger half-brother, also called Ptolemy, became heir apparent and, in 282 BC, ascended to the throne as Ptolemy II. Ptolemy Keraunos had left Egypt and arrived at the court of Lysimachus, the king of Thrace, Macedon, and part of Asia Minor. His half-sister, Arsinoe, later to be named Arsinoe II of Egypt, was wife of Lysimachus.
While staying in the court of Lysimachus, 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.
Seizes the Macedonian Throne
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.
Arsinoe was not happy with the situation. While he was away on a campaign, she conspired against him from the capital, Cassandreia (Greek: Κασσάνδρεια), with the aid of her sons. Keraunos quickly captured Cassandrea, and killed Arsinoe's two younger sons, while the eldest fled north to the kingdom of the Dardanians. Arsinoe herself fled to Egypt, where she married her own brother Ptolemy II and became Arsinoe II.
However, although Ptolemy Keraunos was at the zenith of his power, he did not live long afterwards. In 279 BC, he was captured and killed during the wars against the Gauls led by Bolgius who conducted a series of mass raids against Macedon and the rest of Greece. His death brought anarchy to the Greek states, since none of his successors were able to bring stability. This situation lasted about two years, until Antigonos Gonatas defeated the Gauls in the battle near Lysimachia, Thrace, in 277 BC, After this victory he was recognized king of Macedon and his power extended eventually also to south Greece.
|King of Macedon