In this installment of Crash Course World History, John Green explores the rise of civilization in Mesopotamia, the 'land between two rivers.' The video examines how the geography of the Tigris and Euphrates valleys shaped the culture, religion, and politics of early city-states like Uruk and Babylon. It breaks down foundational developments including the invention of writing (cuneiform), the creation of early legal systems (Hammurabi's Code), and the evolution of political power from temple priests to kings.