Ancient Greece was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (c. AD 600), that comprised a loose collection of culturally and linguistically related city-states and other territories—unified only once, for 13 years, under Alexander the Great‘s empire (336-323 BC).
In Western history, the era of classical antiquity was immediately followed by the Early Middle Ages and the Byzantine period.
