In classical antiquity, the Hellenistic period covers the time in Mediterranean history after Classical Greece, between the death of Alexander the Great in 323 BC and the death of Cleopatra VII, followed by the emergence of the Roman Empire, as signified by the Battle of Actium in 31 BC and the conquest of Ptolemaic Egypt the following year. The Ancient Greek word Hellas was gradually recognized as the name for Greece, from which the word Hellenistic was derived. "Hellenistic" is distinguished from "Hellenic" in that the latter refers to Greece itself, while the former encompasses all ancient territories under Greek influence, in particular the East after the conquests of Alexander the Great.

Classical Greece was a period of around 200 years in Ancient Greece, marked by much of the eastern Aegean and northern regions of Greek culture gaining increased autonomy from the Persian Empire; the peak flourishing of democratic Athens; the First and Second Peloponnesian Wars; the Spartan and then Theban hegemonies; and the expansion of Macedonia under Philip II. Much of the early defining mathematics, science, artistic thought, theatre, literature, philosophy, and politics of Western civilization derives from this period of Greek history, which had a powerful influence on the later Roman Empire. Part of the broader era of classical antiquity, the classical Greek era ended after Philip II's unification of most of the Greek world against the common enemy of the Persian Empire, which was conquered within 13 years during the wars of Alexander the Great, Philip's son.