The ancient kingdom known for its advanced irrigation systems in Mesopotamia is Sumer. Approximately emerging around 4500 BCE, Sumer is considered one of the world's earliest civilizations, situated in the southern part of modern-day Iraq. The Sumerians developed complex irrigation techniques, harnessing the waters of the Tigris and Euphrates rivers to support agriculture in an otherwise arid landscape. This advancement led to surplus food production, fostering urbanization and the rise of city-states such as Ur, Uruk, and Eridu. Sumer's contributions to writing, law, and governance laid the foundational elements for subsequent civilizations in Mesopotamia.