Located in southern Europe, Greece forms an irregular-shaped peninsula in the Mediterranean with two additional large peninsulas projecting from it: the Chalcidice and the Peloponnese. The Greek islands are generally subdivided into two groups, according to location: the Ionian islands (including Corfu, Cephalonia, and Leucas) west of the mainland and the Aegean islands (including Euboea, Samos, Chios, Lesbos, and Crete) to the east and south. North-central Greece, Epirus, and western Macedonia are all mountainous.
Indo-European peoples, including the Mycenaeans, began entering Greece about 2000 B.C. and set up sophisticated civilizations. About 1200 B.C., the Dorians, another Indo-European people, invaded Greece, and a dark age followed, known mostly through the Homeric epics. At the end of this time, classical Greece began to emerge (c. 750 B.C.) as a loose composite of city-states with a heavy involvement in maritime trade and a devotion to art, literature, politics, and philosophy. Greece reached the peak of its glory in the 5th century B.C., but the Peloponnesian War (431–404 B.C.) weakened the nation, and it was conquered by Philip II and his son Alexander the Great of Thessaloniki Macedonia. By the middle of the 2nd century B.C., Greece had declined to the status of a Roman province. It remained within the eastern Roman Empire until Constantinople fell to the Crusaders in 1204. In 1453, the Turks took Constantinople and by 1460, Greece was a province in the Ottoman Empire. The Greek war of independence began in 1821, and by 1827 Greece won independence with sovereignty guaranteed by Britain, France, and Russia.