Chares, in command of the Athenian forces, is joined in 356 BCE in the waters off Byzantium by veteran generals Iphicrates and Timotheus with reinforcements.

The Athenians subsequently lose a battle at Embata, after which Chares, having blamed the defeat on his colleagues, is left sole commander.

After receiving no supplies from Athens, however, he joins the insurgent Persian satrap Artabazus.

Artaxerxes, in an early indication of the vigor with which the Persian king intends to rule, in 356 orders all the satraps of the Achaemenid empire to dismiss their mercenary armies, many of whom are Greek, thus preempting future trouble of the same sort.

Myrtale probably took the name Olympias, the third of four names by which she will be known, as a recognition of Philip's horse-race victory in the Olympic Games of 356 BCE, the news of which coincided with the birth of her first child, who will become known to posterity as Alexander the Great. (Plut. Alexander 3.8).

In ancient Greece people believe that the birth of a great man is accompanied by portents.

As Plutarch describes, the night before the consummation of their marriage Olympias had dreamed that a thunderbolt fell upon her womb and a great fire was kindled, its flames dispersed all about, then extinguished.

After the marriage Philip had dreamed that he put a seal upon his wife's womb, the device of which was the figure of a lion.

The interpretation of Aristander, a seer in Philip's entourage, had been that Olympias was pregnant of a son whose nature would be bold and lion-like.

Plato writes two dialogues in 356 BCE: the Timaeus and the Critias, the earliest known reference to Atlantis.

In the Timaeus, which presents a semi-mythical description of the origin and nature of the universe, Plato recounts the tale of Egyptian priests who two-hundred years earlier had reportedly described Atlantis as a powerful island empire seeking to dominate the Mediterranean world more than nine thousand years before Plato's time.

The Atlantans’ plans for expansion were ended only when Athens defeated their army.

Shortly afterward, a violent earthquake caused Atlantis to sink beneath the ocean.

Greatly influenced by Pythagorean number theory, Plato describes in the Timaeus the soul of the world as structured according to the musical ratios that the Pythagoreans see as governing forces in the cosmos as well as in sounds.

Plato applies the name Demiurge—the Greek word for artisan or craftsman—to God the creator, the divine craftsman who brought order out of a primeval chaos.

According to Plato, our world is but an imperfect copy of the real world of ideas impressed onto matter by the Demiurge; the universe is thus a combination of matter and perfect ideas.

In the Critias, Plato characterizes Atlantis as possessed of an ideal political system.

Philip, having restored order in Macedon, proclaims himself King Philip II in 356 BCE, and moves on to conquer …

…Pydna on the Thermaic Gulf and …

…the west Thracian mining city of Krenides, or Daton, in the foothills south of Mount Orbelos (modern Lekani), a place newly founded (360) by Callistratus, together with a group of colonists from Thasos, on an old Thasian settlement to exploit new finds of silver and gold in Mount Pangaion, whose famed wealth the Thracians have heretofore exploited, trading their metals for goods supplied by the Amphipolitans and Neapolitans.

The small colony, threatened by Thracian tribes, had called on Philip II for aid in 356, leading to the refoundation of the city as Philippi.

After the takeover of the area by Philip, Callistratus takes refuge in Byzantium. (Upon his return to Athens later in the 350s, he will be executed.)

The Thebans, having suffered a reverse on Euboea in 357 BCE when Athenian ascendancy had suddenly and humiliatingly replaced Theban, seek a victim, and Phocian behavior offers an excuse.

The Phocians, who still control the oracle at Delphi, had taken part in Epaminondas' campaigns in the Peloponnese in the early 360s but in 362 had refused to send a contingent in the successful campaign of Mantineia.

In return for this negligence, the Thebans, who since 364 BCE have had influence over the preponderance of votes in the Delphic Amphictyony, in autumn 357 BCE persuade the Thessalian members to condemn Phocis to a huge fine for the usual technical offense, cultivating land sacred to Apollo.

The hope is that if, or rather when, Phocis proves unable to pay, Thebes will be awarded the conduct of the Sacred War that is sure to ensue.

Furthermore, the league belatedly assesses a fine of five hundred talents against Sparta for its seizure of the Cadmeia at Thebes in 382 BCE, a time of peace; it is doubled when the Spartans do not pay.

Phocis, led by Philomelus, also refuses to pay, instead using a secret grant of fifteen talents from Spartan king Archidamus III to hire mercenaries, …

…who in 356 BCE capture for Phocis the Delphic shrine and its treasury.

Most of the Delphians are not hurt, but the resisting clan of Thracidae is put to death.

The neighboring Locrians make an unsuccessful attempt to dislodge the Phocians.