section_path: Heir of Philip II/Regency and ascent of Macedon
section_name: Regency and ascent of Macedon
paragraph_text: Regency and ascent of Macedon
  
  At the age of 16, Alexander's education under Aristotle ended. Philip II had waged war against the Thracians to the north, which left Alexander in charge as regent and heir apparent. During Philip's absence, the Thracian tribe of Maedi revolted against Macedonia. Alexander responded quickly and drove them from their territory. The territory was colonized, and a city, named Alexandropolis, was founded.
  
  Upon Philip's return, Alexander was dispatched with a small force to subdue the revolts in southern Thrace. Campaigning against the Greek city of Perinthus, Alexander reportedly saved his father's life. Meanwhile, the city of Amphissa began to work lands that were sacred to Apollo near Delphi, a sacrilege that gave Philip the opportunity to further intervene in Greek affairs. While Philip was occupied in Thrace, Alexander was ordered to muster an army for a campaign in southern Greece. Concerned that other Greek states might intervene, Alexander made it look as though he was preparing to attack Illyria instead. During this turmoil, the Illyrians invaded Macedonia, only to be repelled by Alexander.
  
  Philip and his army joined his son in 338 BC, and they marched south through Thermopylae, taking it after stubborn resistance from its Theban garrison. They went on to occupy the city of Elatea, only a few days' march from both Athens and Thebes. The Athenians, led by Demosthenes, voted to seek alliance with Thebes against Macedonia. Both Athens and Philip sent embassies to win Thebes's favour, but Athens won the contest. Philip marched on Amphissa (ostensibly acting on the request of the Amphictyonic League), capturing the mercenaries sent there by Demosthenes and accepting the city's surrender. Philip then returned to Elatea, sending a final offer of peace to Athens and Thebes, who both rejected it.
  
  As Philip marched south, his opponents blocked him near Chaeronea, Boeotia. During the ensuing Battle of Chaeronea, Philip commanded the right wing and Alexander the left, accompanied by a group of Philip's trusted generals. According to the ancient sources, the two sides fought bitterly for some time. Philip deliberately commanded his troops to retreat, counting on the untested Athenian hoplites to follow, thus breaking their line. Alexander was the first to break the Theban lines, followed by Philip's generals. Having damaged the enemy's cohesion, Philip ordered his troops to press forward and quickly routed them. With the Athenians lost, the Thebans were surrounded. Left to fight alone, they were defeated.
  
  After the victory at Chaeronea, Philip and Alexander marched unopposed into the Peloponnese, devastating much of Laconia and ejecting the Spartans from various parts of it. At Corinth, Philip established a "Hellenic Alliance" (modelled on the old anti-Persian alliance of the Greco-Persian Wars), which included most Greek city-states except Sparta. Philip was then named Hegemon (often translated as "Supreme Commander") of this league (known by modern scholars as the League of Corinth), and announced his plans to attack the Persian Empire.