Ancient civilizations first developed along major rivers like the Tigris and Euphrates in Mesopotamia over 5,500 years ago. Writing was invented to manage production, land, and taxes. Mesopotamian cities had streets, squares, and temples like ziggurats. Greek civilization arose around 3,000 years ago with prosperous city-states like Athens and Sparta. The Greeks invented democracy and held the first Olympic Games. The Roman Empire spread across Europe and the Mediterranean, building cities and monuments while Latin became the dominant language.