Mesopotamia, located in modern-day Iraq, was home to some of the earliest civilizations and major developments in human history. It consisted of two main regions, Assyria in the north and Sumer in the south, which were organized into city-states ruled by kings with the assistance of councils of elders from powerful families. Cities centered around ziggurats and temples and were connected by roads, leading to growth of trade but also conflicts. Notable Mesopotamian developments included the earliest systems of writing in the form of cuneiform on clay tablets, advances in fields like medicine, the invention of the wheel initially for pottery rather than transportation, and the establishment of the first legal codes