Beginning in the nineteenth century, excavations in Iraq, Syria, and Iran have brought to light the remains of the civilizations that flourished in the ancient Near East in the third to first millennia BCE. Text are available in three ancient Near Eastern languages: Sumerian, Assyrian, and Babylonian. Ancient Mesopotamian societies were complex peasant societies: strongly stratified, state-building societies characterized by a comparatively high degree of urbanization. The environmental conditions determined to a large extent the economic activities. A two-sector paradigm of the Mesopotamian economy has been developed predominantly on the basis of evidence from the third millennium BCE. The model's most sustained challenges come from the documentation for long-distance (and domestic) trade that proves the existence of market-based and profit-oriented commerce supported by complex social and legal institutions, and from evidence dating to the first millennium BCE that shows a period of economic growth driven, inter alia, by increasing monetization and the market orientation of economic exchange.