Ancient Greece was located in Southeastern Europe and had a mountainous landscape divided by seas. This geography led Greeks to form independent city-states like Athens and Sparta. Athens developed the world's first democracy while Sparta was a strict military state. During the Golden Age of Greece, Athens grew powerful but clashed with other city-states, weakening Greece. Meanwhile, Macedonia rose to power under Alexander the Great, who conquered the Persian Empire and spread Greek culture widely, establishing the Hellenistic period of cultural blending and scientific/mathematical discoveries.