Expansion of Macedonia under Philip II

Expansion of Macedonia under Philip II
The Kingdom of Macedon in 336 BC
Date 359–336 BC Location Thrace, Illyria, Greece, Asia Minor Result Macedonian victory
Belligerents
Macedon	Greek city states Illyrians Thracians
Commanders and leaders
Philip II Alexander III	Various

Under the reign of Philip II (359–336 BC), the ancient kingdom of Macedonia, initially at the periphery of classical Greek affairs, came to dominate Ancient Greece in the span of just 25 years, largely thanks to the character and policies of its king.^[1] In addition to utilising effective diplomacy and marriage alliances to achieve his political aims, Philip II was responsible for reforming the ancient Macedonian army into an effective fighting force. The Macedonian phalanx became the hallmark of the Macedonian army during his reign and the subsequent Hellenistic period. His army and engineers also made extensive use of siege engines. Chief among Philip's Thracian enemies was the ruler Kersebleptes, who may have coordinated a temporary alliance with Athens. In a series of campaigns stretching from 356 to 340 BC, Philip II managed to ultimately subjugate Kersebleptes as a tributary vassal, conquering much of Thrace in the process. Philip II also fought against the Illyrian king Bardylis, who threatened Macedonia proper, and against Grabos II and Pleuratus in Illyria (centred in modern-day Albania). In his newly conquered territories, he founded new cities such as Philippi, Philippopolis (modern Plovdiv, Bulgaria), Herakleia Sintike (Pirin Macedonia, Bulgaria), and Herakleia Lynkestis (modern Bitola, North Macedonia).

Philip II eventually campaigned against the city-state of Athens and her allies in the Aegean region, as well as Thebes after the decline of its hegemony in mainland Greece. In the defence of the Amphictyonic League of Delphi and in conjunction with the Thessalian League, Macedonia became a key player in the Third Sacred War (356–346 BC), defeating the Phocians, commanded by Onomarchus, at the Battle of Crocus Field in 352 BC. While poised to launch a direct assault on Athens in 346 BC, the Macedonian king was met with an Athenian embassy that arranged the Peace of Philocrates. As a result, Macedonia and Athens became allies, yet Athens was forced to relinquish its claims to the city of Amphipolis (in modern-day Central Macedonia).

The Peace of Philocrates eventually broke down as hostilities reignited between Athens and Macedonia. Demosthenes, an Athenian statesman who was partially responsible for engineering the peace treaty, delivered a series of speeches encouraging his fellow Athenians to oppose Philip II. The Macedonian hegemony over Greece was secured by their victory over a Greek coalition army led by Athens and Thebes, at the Battle of Chaeronea in 338 BC. In the aftermath the federation of Greek states known as the League of Corinth was established, which brought these former Greek adversaries and others into a formal alliance with Macedonia. The League of Corinth elected Philip as strategos (i.e. commander-in-chief) for a planned invasion of the Achaemenid Empire of Persia. However, Philip was assassinated before he could begin the campaign, a task that instead fell to his son and successor, Alexander the Great.