Third Sacred War
The Third Sacred War (356–346 BC) was fought between the forces of the Delphic Amphictyonic League, principally represented by Thebes, and latterly by Philip II of Macedon, and the Phocians. The war was caused by a large fine imposed in 357 BC on the Phocians by the Amphictyonic League (dominated at that moment by Thebes), for the offense of cultivating sacred land; refusing to pay, the Phocians instead seized the Temple of Apollo in Delphi, and used the accumulated treasures to fund large mercenary armies. Thus, although the Phocians suffered several major defeats, they were able to continue the war for many years, until eventually all parties were nearing exhaustion. Philip II used the distraction of the other states to increase his power in northern Greece, in the process becoming ruler of Thessaly. In the end, Philip's growing power, and the exhaustion of the other states, allowed him to impose a peaceful settlement of the war, marking a major step in the rise of Macedon to pre-eminence in Ancient Greece.
Third Sacred War
Meanwhile, Onomarchos returned to Thessaly to try to preserve the Phocian ascendancy there, with approximately the same force as during the previous year. Furthermore, the Athenians dispatched Chares to help their Phocian allies, seeing the opportunity to strike a decisive blow against Philip. Subsequent events are unclear, but a battle was fought between the Macedonians and the Phocians, probably as Philip tried to prevent the Phocians uniting forces with the Pheraeans, and crucially, before the Athenians had arrived. According to Diodorus, the two armies met on a large plain near the sea, probably in the vicinity of Pagasae. Philip sent his men into battle wearing crown of laurel, the symbol of the Apollo; "as if he was the avenger...of sacrilege, and he proceeded to battle under the leadership, as it were, of the god". In the ensuing battle, the bloodiest recorded in ancient Greek history, Philip won a decisive victory against the Phocians. In total, 6,000 Phocian troops were killed including Onomarchos, and another 3,000 taken prisoner. Onomarchos was either hanged or crucified and the other prisoners drowned, as ritual demanded for temple-robbers. These punishments were designed to deny the defeated an honourable burial; Philip thus continued to present himself as the pious avenger of the sacrilege committed by the Phocians.