The Assyrian Empire started off as a major regional power in Mesopotamia in the second millennium B.C.E., but later grew in size and stature in the first millennium B.C.E. under a series of powerful rulers, becoming one of the world’s earliest empires.

Assyria was located in the northern part of Mesopotamia, which corresponds to most parts of modern-day Iraq as well as parts of Iran, Kuwait, Syria, and Turkey. It had relatively humble beginnings as a nation-state early in the second millennium B.C.E. Its status underwent many changes; though sometimes it was an independent state, it also fell to the Babylonian Empire, and later to Mittani rule. But unlike other nation-states, because of their technological advances in warfare, the Assyrians maintained their land while other states and empires rose and fell from power. When another group, the Hittites, rose to power and overthrew Mittani rule, it left a power vacuum that sent the region into war and chaos. This left the Assyrians poised to gain more power in the region. Around 900 B.C.E., a new series of Assyrian kings, beginning with Adad Nirari II, rose to prominence and expanded Assyria’s borders into a huge empire.

Adad Nirari II and his successors used new warfare techniques to take over enemy cities one by one. The Assyrians had several advantages that they had been developing for generations while other empires came and went. They were the first in the area to develop iron weapons, which were superior to the bronze weapons their enemies were using. Their skill at ironworking allowed them to make weapons and protective items more cheaply, so more soldiers could use them. In addition, they were the first army to have a separate engineering unit, which would set up ladders and ramps, fill in moats, and dig tunnels to help the soldiers get into a walled city. They were also among the first to build chariots, which provided greater protection on the battlefield. These technological advancements allowed the Assyrians to go on the offensive and attack neighboring areas for the first time, which led to the expansion of their empire.

The Assyrian Empire maintained power for hundreds of years. But in the 600s B.C.E., the empire became too large to maintain, and it fell apart. Even after its fall, the empire’s legacy lived on in the warfare tactics and technologies that were adopted by later civilizations.