Region of northern Mesopotamia located on the upper Tigris River and center of two influential empires in ancient Southwest Asia. The region took its name from Assur, the original capital of the first of these empires. The Assyrians built the largest standing army in the region and used it to control northern Mesopotamia from about 2000 B.C.E. to 612 B.C.E.

The earliest evidence of Assyrian kingship dates to ca. 2000 B.C.E., but the first king to project Assyrian power was Shamshi-Adad I (r. 1808–1776 B.C.E.). He conquered neighboring territories and consolidated royal authority over all northern Mesopotamia. Assyria's location, trade, and military power brought it into conflict with the Babylonian kingdom to the south. Babylonia's king Hammurabi (r. 1792–1750 B.C.E.) conquered Assyria shortly after assuming the throne.

Babylon's dominance of Assyria lasted a century, during which time Assyria broke into a number of smaller

territories ruled by vassal kings dependent on the Babylonians. Ashuruballit I (r. ca. 1365–1330 B.C.E.) conquered these lands to create the first true Assyrian Empire, reigniting a rivalry between Assyria and Babylon that lasted until the twelfth century B.C.E. In 1120 B.C.E., the Assyrian king Tiglath-Pileser I (r. ca. 1115–1076 B.C.E.) began a new period of territorial conquest and eventually ruled over a region stretching from the Mediterranean Sea in the west to the Tigris River in the east and as far north as the Black Sea.

The kings who succeeded Tiglath-Pileser I were politically weak, and for the next two centuries Assyria fought for dominance of the region with the neighboring kingdom of Urartu and endured invasions by Aramean nomads from the south. Assyria's fortunes rebounded under King Ashurnasirpal II (r. ca. 883–859 B.C.E.), who established the second Assyrian Empire. He conquered the Arameans and reasserted Assyrian control from the Mediterranean Sea to the Euphrates River. Under Ashurnasirpal II, the Assyrians built the largest professional standing army seen to date and developed a reputation as superior warriors.

The rulers who followed Ashurnasirpal II built on his success, but by the early eighth century B.C.E., the familiar pattern of internal conflict, invasion, and weak kings followed by stronger rulers was reestablished. It ended only 612 B.C.E. when the Babylonian king Nabopolassar (r. 626–605 B.C.E.) invaded and destroyed the Assyrian Empire.

The king's power came from his dual roles as head of the military and high priest to Ashur, the god of war and the most important of the Assyrian gods. However, while brutal in warfare, Assyrian kings also encouraged the spread of learning, architecture, and art that celebrated their military successes and interaction with their gods. Ashurnasirpal II oversaw a flowering of art and architecture in Assyria, sponsoring the construction of monumental building projects such as the botanical and zoological gardens and the Great Ziggurat in the city of Nimrud. He also built a library in Nineveh filled with cuneiform tablets containing religious texts, literature, and scientific findings.