Iraq, a country located in West Asia, largely coincides with the ancient region of Mesopotamia, often referred to as the cradle of civilization. The history of Mesopotamia extends back to the Lower Paleolithic period, with significant developments continuing through the establishment of the Caliphate in the late 7th century AD, after which the region became known as Iraq. Within its borders lies the ancient land of Sumer, which emerged between 6000 and 5000 BC during the Neolithic Ubaid period. Sumer is recognized as the world's earliest civilization, marking the beginning of urban development, written language, and monumental architecture. Iraq's territory also includes the heartlands of the Akkadian, Neo-Sumerian, Babylonian, Neo-Assyrian, and Neo-Babylonian empires, which dominated Mesopotamia and much of the Ancient Near East during the Bronze and Iron Ages.