The Sacred War

When the Phocians sack the Oracle at Delphi and steal Apollo’s treasure, which belongs to Athens, Thebes and Corinth, the Greeks declare a sacred war against the defilers of the oracle. Philip allows Athens, Thebes and Phocis to exhaust themselves during a decade of fighting before stepping in to broker a peace between them. 
Having brought most of the Hellenic world under his rule he fights one last battle against Athens and Thebes during which his son, the eighteen year old Alexander, plays a crucial role.