The continuous troubles in the west cause Seleucid control in the far eastern part of the empire to weaken.

Antiochus makes his eldest son king in the east in 280, but he proves incompetent.

Ptolemy Keraunus had cajoled his half-sister into marrying him, but, on entering Cassandreia, he had promptly executed her two younger sons.

Arsinoe escapes.

Philetaerus has enjoyed a far larger measure of independence than he had hitherto enjoyed under Lysimachus.

The territory Philetaerus controls is as quite small—no more than Pergamon and its environs—and it is largely of necessity that he curries favor with the first Seleucid kings.

His gifts to the temples at Delphi, Greece, and on the island of Delos, in the Aegean Sea, secure for his family some prestige outside of Anatolia.

The slackening of the Seleucid grip on Asia Minor presents Philetaerus with the opportunity to increase the area under his control.

The Pharos of Alexandria, built by Sostratus of Cnidus, perhaps for Ptolemy I Soter, is finished during the reign of Soter's son Ptolemy II of Egypt in about 280 BCE.

The lighthouse, which stands on the island of Pharos in the harbor of the new city, is said to have been more than three hundred and fifty feet (one hundred and ten meters) high; the only taller man-made structures at this time would be the ancient pyramids of Giza.

Its base proclaims that the architect dedicated it to the "savior gods" on behalf of navigators.

One of the Seven Wonders of the World and the most famous lighthouse in antiquity, the four hundred foot-high (one hundred and twenty-two meters) tiered stone tower shields constant fires of resinous wood or oil, reflected by metal mirrors, thus rendering them visible for possibly thirty miles (about fifty kilometers).

A technological triumph, it is to remain the archetype of all lighthouses since.

Ephesus had revolted after the treacherous death of Agathocles, giving the Hellenistic king of Syria and Mesopotamia Seleucus I Nicator in 281 BCE an opportunity for removing and killing Lysimachus, his last rival, at the Battle of Corupedium.

The town again is named Ephesus after the death of Lysimachus, and thus becomes part of the Seleucid Empire.

The twelve Achaean cities of the northern Peloponnese had organized a league by the fourth century BCE to protect themselves against piratical raids from across the Corinthian Gulf, but this league had fallen apart after the death of Alexander the Great.

The ten surviving cities—Dyme, Patrae, Tritaea, and Pherae; joined by Aegium, Bura, and Cerynea—renew their alliance in 280 BCE.

This second, more powerful Achaean league, headed now by a single general instead of two, comprises the cities of Achaea and most of the rest of the Peloponnesus except for Corinth, which remains a Macedonian possession, and Sparta, which remains independent.

Annual voting for leadership is by cities, with representation proportionate to population.

Patras (Greek: Patrai), an important commercial center located on the northern shore of the Peloponnesus, about one hundred miles (one hundred and eighty kilometers) west of Athens, is the primary city among the league’s Peloponnesian participants.

Cineas, a Thessalian who serves as chief adviser to Pyrrhus, attempts, without success, to dissuade Pyrrhus from crossing to Italy in 281 BCE with twenty elephants and about twenty-five thousand highly trained soldiers.

In the first meeting of Roman and Greek armies, Pyrrhus wins a complete, if costly, victory in 280 BCE over a Roman army at Heraclea.

After stirring up revolt among the Samnites, he sends Cineas to Rome to negotiate a peace.

Ptolemy II Philadelphus, the second Macedonian king of Egypt, attacks the Syrian forces of Antiochos at their capital, Damascus, badly defeating them in 279 and gaining a sizable amount of territory in Palestine.

Ptolemy's aggressions cause continuous friction with Antiochus, who in 279 somehow loses Miletus, in southwestern Asia Minor, to Ptolemy.

Macedon again falls into a state of internal confusion, intensified by a coalition of Gallic (Celtic) and Thracian marauders from the north, under the command of Bolgius, who overrun the country.

Ptolemy Keraunus offers battle and is captured and decapitated.