The document discusses the emergence of city-states in ancient Greece following a period of darkness. After Dorian invaders defeated the Mycenaeans around 1200 BCE, Greece entered a 400 year dark age where no writing occurred. Around 800 BCE, small villages began banding together to form trading centers called city-states, and hundreds emerged across Greece. Each city-state had its own identity and government, and citizens were fiercely loyal to their own city over any sense of national identity. The Acropolis in Athens housed important temples and monuments.