Thermopylae (323 BCE)

Immediately after the death of Alexander the Great, the Athenians revolted. They had been preparing the war for some time and were joined by several other Greek towns. A mercenary leader named Leosthenes occupied Thermopylae, where he intended to meet the Macedonian forces.

When Antipater, learned of the movement, he left Sippas as general in Macedonia, giving him a sufficient army and bidding him to enlist as many men as possible, while he himself, taking thirteen thousand Macedonians and six hundred horsemen [...] set out to Thessaly, accompanied by the entire fleet which Alexander had sent to convoy a sum of money from the royal treasury to Macedonia, being in all one hundred and ten triremes. At first the Thessalians were allies of Antipater and sent out to him many good horsemen; but later, won over by the Athenians, they rode off to Leosthenes and, arrayed with the Athenians, fought for the liberty of the Greeks. Now that this great force had been added to the Athenians, the Greeks, who far outnumbered the Macedonians, were successful. Antipater was defeated in battle, and subsequently, since he neither dared to engage in battle nor was able to return in safety to Macedonia, he took refuge in Lamia.^note[Diodorus, of Sicily, World History, 18.12.2-4; tr. R.M. Geer.]

This was the beginning of the Lamian War, which, in spite of the initial success, ended in a disaster for the Greeks.