Early humans lived as hunter-gatherers for millions of years before settling into agricultural villages during the Neolithic Revolution around 8000 BC. This led to the rise of civilization, with specialized jobs, social classes, governments, religions, and art. The first major civilizations emerged in Mesopotamia and Egypt along major rivers from 3000 BC. They developed writing, legal codes, empires, and major architectural achievements like the pyramids. Other important early peoples included the Phoenicians, Israelites, Assyrians, Chaldeans, and Persians.