The death of Macedon's king Amyntas III in 370/369 BCE has left three lawful sons, of whom the first two, Alexander II and Perdiccas III, will rule only briefly.

Thus, neither Thessaly nor Macedon will be in a position to tilt the balance of power in central and northern Greece, but both are valuable prizes.

Macedon has shipbuilding timber and great natural resources (though few outlets to the sea because Greek colonial poleis stand in the way); …

…Thessaly is not only enormously fertile but also has good harbors and religious influence in the Delphic amphictyony.

The tyranny of Alexander of Pherae, successor to the murdered Jason, causes the intervention of a number of city-states in Thessalian affairs.

Alexander II of Macedon has intervened in the civil war at the request of the Thessalian Aleuadae.

Alexander of Pherae, prepares to meet his enemy in Macedonia but the king anticipates him, and, reaching Larissa, is admitted into the city.

Alexander withdraws to Pherae while the Macedonian king places a garrison in Larissa, as well as in Crannon, which has also come over to him.

Once the bulk of the Macedonian army retires, however, the states of Thessaly, fearing the return and vengeance of Alexander, send for aid to Thebes, whose policy it is to put a check on any neighbor who might otherwise become too formidable.

Thebes accordingly dispatches Pelopidas to the aid of Thessaly.

Pelopidas checks the ambitions of Alexander of Pherae, and drives the forces of the king of Macedon out of Thessaly.

During the successful campaign, …

…Pelopidas takes hostage Philip, the thirteen-year-old brother of Macedon’s king.

Alexander II of Macedon had successfully gained control of Larissa and several other cities but, betraying a promise he had made, had put garrisons in them, provoking a hostile reaction from Thebes, the leading military power in Greece at this time.

The Theban general Pelopidas, after driving the Macedonians from Thessaly, now neutralizes Alexander by favoring the ambitions of Alexander's brother-in-law Ptolemy of Aloros, and forces Alexander to abandon his alliance with Athens in favor of Thebes.

As part of this new alliance, Alexander is compelled to hand over hostages, including his younger brother Philip.

At the instigation of Ptolemy, Alexander is assassinated during a festival.

Although Alexander's brother Perdiccas III becomes the next king, he is under age, and Ptolemy is appointed regent.

On the arrival of Pelopidas at Larissa, whence according to Diodorus, he dislodged the Macedonian garrison, Alexander of Pherae presents himself and offers submission.

When Pelopidas expresses indignation at the tales of Alexander's profligacy and cruelty, the tyrant takes alarm and flees.

These events appear to refer to the early part of the year 368 BCE.

Pelopidas in the summer of this year is again sent into Thessaly, in consequence of fresh complaints against Alexander.

Accompanied by Ismenias, he goes merely as a negotiator, without any military force, and is seized by Alexander and thrown into prison. (The scholar William Mitford suggested that Pelopidas was taken prisoner in battle, but the language of Demosthenes hardly supports such an inference.)

The Thebans send a large army into Thessaly to rescue Pelopidas, but they cannot keep the field against the superior cavalry of Alexander, who, aided by auxiliaries from Athens, pursues them with great slaughter.

The destruction of the whole Theban army is said to only have been averted by the ability of Epaminondas, who is serving in the campaign, but not as general.

Alexander of Pherae carries out a massacre of the citizens of Skotoussa in 367 BCE .

Epaminondas, appointed general for his performance against Alexander in battle, has resulted in his reelection as boeotarch.

Epaminondas now returns to Thessaly with a large army, resulting, according to Plutarch, in a three-year truce and the release of prisoners, including Pelopidas.

Perdiccas kills Ptolemy in 365 BCE and assumes control of Macedon’s government.

Of the reign of Perdiccas we have very little information, knowing only that he was at one time engaged in hostilities with Athens on account of Amphipolis, and that he was distinguished for his patronage of men of letters.

Among these, we are told that Euphraeus, a disciple of Plato, rose to so high a place in his favor as completely to govern the young king, and exclude from his society all but philosophers and geometers.

He also served as Theorodokos (sacred envoy-receivers, whose duty is to host and assist the Theoroi, or "viewers" before Panhellenic Games and Festivals) in the Epidaurian Panhellenic games of about 365 BCE.

The Boeotian league destroys Thebes' Boeotian rival Orchomenus in 364 BCE.

Epaminondas in this year commands a fleet against the Athenian navy and …

…Pelopidas marches against Alexander of Pherae, who, during the past three years, has seemed to renew his attempts to subdue the states of Thessaly, especially Magnesia and Phthiotis, for upon the expiry of the truce in 364 BCE they again apply to Thebes for protection from him.

The Theban army under Pelopidas is said to have been dismayed by an eclipse on July 13, 364, and Pelopidas, leaving the bulk of his army behind, enters Thessaly at the head of three hundred volunteer horsemen and some mercenaries.

At Cynoscephalae (Greek: “Dogs' Heads”), an ancient range of hills in Thessaly, the Thebans defeat Alexander, but Pelopidas is killed.

This is closely followed by another Theban victory under Malcites and Diogiton.

Alexander is now forced to restore the conquered towns to the Thessalians, confine himself to Pherae, join the Boeotian League, and become a dependent ally of Thebes.