Where were the first true slave societies in the world history?

The first true slave societies in world history emerged in ancient civilizations, particularly in Mesopotamia around 3500 BCE, where slavery became institutionalized as a result of agricultural surplus and social stratification. Other early examples include ancient Egypt, Greece, and Rome, where slavery was integral to the economy and social structure. These societies relied on enslaved individuals for labor in various sectors, including agriculture, construction, and domestic work, establishing a legacy of slavery that would influence many cultures throughout history.