Southern Thessaly is the gateway to Greece…

Philip of Macedon in 353 or 352 BCE leads an army of twenty thousand infantrymen and three thousand cavalry on a lightning march against the port of Pagasae, seizing it before the Athenian fleet, commanded by Chares, can dock and unload their five thousand hoplites and five hundred cavalry.

Philip decks his army in laurel wreaths to signify that they fight on behalf of Apollo against the sacrilegious Phocians.

Leaving a rearguard, he marches against Onomarchus, while the Athenians, absent beaches where they can offload their troops, can only watch the battle from their triremes anchored offshore.

Onomarchus and six thousand Phocian soldiers die in the Battle of the Crocus Field, with more drowning as they attempt to swim to the Athenian ships; three thousand more are captured.

The Phocians appoint Phayllus leader and withdraw southwards, pursued by Philip.

Philip continues to move south, employing bribery and threat as well as military force.

The Athenians in response send a small force to close off the pass at Thermopylae.

Philip’s Thessalian victory meanwhile earns him election as president (archon) of the Thessalian League (probably 352), a position unique for a foreigner in a Greek confederation (and one that is to bind Thessaly to the kings of Macedonia for one hundred and fifty years and more).

Having already perhaps been officially recognized as ruler of Thessaly before the Crocus Field, Philip now takes over Thessaly in the full sense, acquiring its ports and its revenues.

A further asset is the Thessalian cavalry (which will be used to augment Macedon's own “companion cavalry” in the great battles of his son Alexander's early years in Asia.)

The Persians burn Sidon in 351 BCE following a revolt against Achaemenid rule.

Artaxerxes, a cruel but energetic ruler, attempts to subjugate Egypt, which has been independent since 404.

Failure in 351 of the first attempt encourages ...

...a revolt of the Phoenician towns and ...

...the princes of Cyprus.

Mausolus has made Halicarnassus the metropolis of his Carian satrapy; the victory of the anti-Athenian coalition in the Social War brings Rhodes and Cos into his sphere of influence.

The architecture of the city, including the satrap's tomb, the Mausoleum of Halicarnassus (one of the Seven Wonders of the Ancient World), shows strong Greek influence.

The mausoleum, an enormous structure containing colossal figures of the Carian king and his queen, is planned by Mausolus himself but is built by his wife and successor, Artemisia II, who is also his sister; she rules from 353.

The architect is Pythius (or Pytheos), and the sculptures that adorn the building are the work of four leading Greek artists: Scopas, Bryaxis, Leochares, and Timotheus.

The temple-like marble tomb features an Ionic colonnade on a high base surrounded by lions; the roof is a twenty-four-step pyramid surmounted by a chariot.

The Mausoleum’s frieze depicts of Amazons battling heroes.

Mausolus' second son Idrieus succeeds his mother in 351 as satrap.

Philip had turned aside to the coast of Thrace, avoiding a direct confrontation with Athens, but his intentions were clear.

Many Athenians, however, continue to believe that Philip's threat was transitory, though not Demosthenes, who in the first half of 351 denounces Philip and Macedonian imperialism in his “First Philippic.” He decries the Athenian moves to counter Philip as always being too little and coming too late, and urges the creation of a task force and larger emergency force.

He reminds the Athenians that they had once defeated the Spartans, who were as strong as Philip, and sarcastically points out that Philip would never have conquered their territories if he were as timid as the Athenians seem to be.

He concludes by challenging his countrymen to take their affairs in their own hands rather than let Philip win by default.

It is not clear how influential Demosthenes' advice is—or how influential, at this stage, it deserves to be: at about the same time, and perhaps actually after the First Philippic, Demosthenes is found advocating, in the Speech on the Freedom of the Rhodians, a foolish diversion of resources to the southeastern Aegean against the encroachments of Mausolus' family.

The situation there is, in fact, beyond repair.

The goading First Philippic fails to rouse the Athenians but they do send a small contingent in September 351 when Philip lays siege to a place called Heraeum Teichos.

Tarquinia wins a truce from Rome in 351 BCE, then allies with Sutri.