Assyria was a Semitic Akkadian kingdom centered on the Upper Tigris river, in northern Mesopotamia (present day northern Iraq), that came to rule regional empires a number of times through history. It was named for its original capital, the ancient city of Assur. Assyria was also sometimes known as Subartu, and after its fall as Athura, Syria and Assuristan. The term Assyria can also refer to the geographic region or heartland where these empires were centered. Their descendants still live in the region today, and they form the Christian minority in Iraq. After the fall of the Akkadian Empire in 2080 BC, it eventually coalesced into two separate nations; Assyria in the north, and later Babylonia in the south.
Originally, the early Assyrian kings would certainly have been regional leaders only, and subject to Sargon of Akkad who united all the Akkadian speaking peoples of Mesopotamia under the Akkadian Empire which lasted from 2334 BC to 2154 BC. The Akkadian nation of Assyria (and later on also Babylonia) evolved from the dissolution of the Akkadian Empire. In the Old Assyrian period of the Early Bronze Age, Assyria had been a kingdom of northern Mesopotamia, competing for dominance with its fellow Mesopotamian rival, Babylonia which was often under Kassite rule. During this period it established colonies in Asia Minor. It had experienced fluctuating fortunes in the Middle Assyrian period.
Beginning with the campaigns of Adad-nirari II from 911 BC, it again became a great power, conquering many of their neighbors. Eventually they weakened after so many wars and their empire would fall in the 10th century B.C.