Expansion of Macedonia under Philip II

Under the reign of Philip II (359–336 BC), the Argead kingdom of Macedonia, initially at the periphery of classical Greek affairs, came to dominate Ancient Greece in the span of less than 25 years, largely thanks to the character and policies of its king. In addition to utilising effective diplomacy and marriage alliances to achieve his political aims, Philip II was responsible for reforming the ancient Macedonian army into an effective fighting force.

Source: Wikipedia — Expansion of Macedonia under Philip II (CC BY-SA 4.0)