Ancient Greece had traditionally been a fractious collection of fiercely independent city-states. After the Peloponnesian War (431–404 BC), Greece had fallen under a Spartan hegemony, in which Sparta was pre-eminent but not all-powerful. Spartan hegemony was succeeded by a Theban one after the Battle of Leuctra (371 BC), but after the Battle of Mantinea (362 BC), all of Greece was so weakened that no one state could claim pre-eminence. It was against this backdrop, that the ascendancy of Macedon began, under king Philip II. Macedon was located at the periphery of the Greek world, and although its royal family claimed Greek descent, the Macedonians themselves were looked down upon as semi-barbaric by the rest of the Greeks. However, Macedon had a relatively strong and centralised government, and compared to most Greek states, directly controlled a large area.

When was the Peloponnesian War?