Assyria was a major kingdom or empire of the Ancient Near East, existing in various forms during a period of more than 15 centuries, between Middle Bronze Age and the Iron Age. Centered on the Upper Tigris river, in northern Mesopotamia, the Assyrians came to rule powerful empires at several times. As substantial part of the greater Mesopotamian "cradle of civilization", Assyria was at the height of cultural achievements for its time.
Assyria is named for its original capital, the ancient city of Aššur (located in what is now the Saladin Province of Iraq), originally one of a number of Akkadian city states in Mesopotamia. In the late 24th century BC, Assyrian kings were regional leaders only, and subject to Sargon of Akkad, who united all the Akkadian Semites and Sumerian-speaking peoples of Mesopotamia under the Akkadian Empire, which lasted from c. 2334 BC to 2154 BC.
Following the fall of the Akkadian Empire c. 2154 BC, and the succeeding Sumerian Third Dynasty of Ur, there were a number of other competing Amorite states, such as Isin and Larsa, but Mesopotamia eventually coalesced into two distinct nations: Assyria in the north, and Babylonia in the south.