The Battle of Chaeronea took place on 2 August 338 BC in Boeotia (central Greece). The armies of Philip II. Macedon and a coalition of Athens, Thebes and their allies. Philip's victory established Macedonian hegemony in Greece.
The Macedonian army of about 32,000 men was smaller in number, but more experienced and, above all, had a better quality of warlord. The coalition warlords were mostly dead (Ifikrates, Chabrias or Timotheos), leaving the not-so-good Chares.
The battle itself was very even until Philip withdrew the troops on his right flank. On top of this, his son Alexander broke through the Greek defences on the left flank, and confusion ensued among the Greeks. The Athenians fled and the Thebans were surrounded. Of the famed Theban holy band (numbering 300 men), 254 were killed and the rest captured. Historians give the main credit for the victory to Alexander of Macedon.
This victory established Macedonian supremacy over the Greek states and also marked the formation of the Corinthian League, which was led by Philip. The defeated Greeks were treated exceedingly well. Despite this, King Philip was assassinated and the Thebans attempted to rise up against the Macedonians. They were punished for this by Alexander's soldiers in 335 BC, when their entire city was destroyed.
The battle itself and the formation of the Corinthian League is considered the beginning of the Macedonian outbreak against the Persian Empire in the east, which occurred a few years later.