This document provides a summary of early river valley civilizations between 3500 BC and 450 BC. It covers the civilizations that emerged in Mesopotamia, Egypt, the Indus Valley, and China. In Mesopotamia, the Sumerians established the first cities and city-states like Uruk and Kish around 3000 BC. They developed irrigation, laws, writing, and a social hierarchy. In Egypt, King Narmer unified Upper and Lower Egypt around 3000 BC and established the first dynasty. The Egyptians built pyramids and large tombs for pharaohs and developed hieroglyphic writing. Along the Indus River, the Harappan civilization established well-planned cities with