More than 2,500 years after the fall of the Assyrian Empire, archaeological discoveries continue to reveal new details about its powerful kings and the grandeur of its capital. In July 2026, a rare, well-preserved inscription stone was unearthed in Iraq detailing the achievements of the powerful Assyrian king Ashurbanipal. It was found amid the ruins beneath the modern Iraqi city of Mosul, which was built atop the Neo-Assyrian capital of Nineveh. The find followed the discovery of the names of three previously unknown Assyrian kings, further deepening historians' understanding of the empire.

Here's what made the Assyrians so dominant in ancient Mesopotamia.

They had a strong military

The Assyrian military transformed Assyria into the world's first military superpower. Its power peaked during the empire's Neo-Assyrian phase, between 911 and 609 B.C., largely thanks to the reforms of King Tiglath-Pileser III, who established the first professional standing army around 745 B.C. This move allowed for year-round campaigning.

Related: Brief History of Assyrians

The Assyrian military also developed a knee-high heavy military boot for harsh terrain and was the first to equip its soldiers with iron weapons, giving them a decisive edge over armies still using more expensive bronze weapons. The Assyrians organized their armies into infantry, cavalry and missile units--archers and slingers--and mastered siege warfare against fortified enemy cities. The Assyrian military was also expert at spreading systematic terror, mass deportations and other forms of psychological warfare, tactics that later influenced military powers including the Romans.

They benefitted from innovation

The Assyrians absorbed and built on earlier Mesopotamian achievements, beginning with the Sumerians around 5000 B.C. By the time of the Neo-Assyrian Empire, which emerged in the 10th century B.C., the Assyrians had adopted many key innovations from their predecessors, including writing, mathematics, engineering and complex legal codes.

Related: Assyrians: Frequently Asked Questions

The Library of Ashurbanipal, which archaeologists discovered in the 19th century at Nineveh, near modern-day Mosul, contained thousands of texts that had been systematically collected, translated and copied from across Mesopotamia, including the Epic of Gilgamesh--an epic poem dating to roughly 2100 B.C. that tells the story of an earlier Sumerian king of that name. These texts were written in cuneiform on clay tablets and can still be read today.

"We have literally tens of thousands of texts from Assyria," says Assyriologist Eckart Frahm of Yale University. "Fortunately for us they wrote on clay, and clay, once sun-dried, is almost indestructible."

They had (a) God on their side

Like other Mesopotamian civilizations, the Assyrians had a pantheon of gods with their own patron deity, Ashur, in the top spot. The gods of conquered peoples, such as those of Babylon or Ur, might be admitted to the Assyrian pantheon, but at a lower rank than Ashur and the other major deities. Assyria's king styled himself as the steward or viceroy of the chief god, and this religious unity--enforced by the state--helped bind the Assyrian Empire together.

Assyria is the villain in parts of the Bible, and Ashur is often presented as powerless against the Israelite god Yahweh. A famous episode occurred when the Neo-Assyrians under King Sennacherib besieged Jerusalem in 701 B.C., an event immortalized by Lord Byron in his 1815 poem "The Destruction of Sennacherib":

The Assyrian came down like the wolf on the fold,
And his cohorts were gleaming in purple and gold;

According to the Bible, a plague sent by Yahweh struck the Assyrian army overnight, causing many soldiers to die and the siege to be abandoned. But the plague account may be a story. Both Assyrian records and the Bible say that Jerusalem paid a massive tribute in gold and silver to the Assyrians, Frahm says, which may explain why the Assyrians did not sack the city.

Their time had come

The Assyrians first appeared around 2900 B.C. as traders from the northern city of Ashur, which was named for their chief god. Around 1800 B.C., they emerged as a regional power under the Amorite conqueror Shamshi-Adad I.

As their kingdom expanded, the Assyrian capital moved several times, from Ashur to Kalhu (Nimrud), then to Dur-Sharrukin (Khorsabad). The empire reached the height of its power after 702 B.C., when King Sennacherib established a new capital at Nineveh.

The Assyrian Empire eventually crumbled under weak rulers, and for a time Babylon was ascendant again. But the Neo-Babylonians never equaled the power or prominence of the Neo-Assyrians.

Their rulers created a stable system

The Assyrians may have been the greatest of Mesopotamian cultures, and their Neo-Assyrian phase represented a high point of civilization in the ancient Near East. At its height, the Assyrian Empire was the largest the region had ever seen, stretching from western Iran to the Mediterranean coast and even into Egypt. Its ruling mechanisms served as a blueprint for many ancient empires that came later, including the Romans.

Assyria did not just conquer Mesopotamia--it codified and archived much of its intellectual legacy. It also appears to have overcome the typical fragility of Mesopotamian states through firm leadership, says Assyriologist Philip Jones, a curator at the Penn Museum. "Somehow, [Assyria] created a more stable provincial system," he says, "where new kings did not meet automatic rebellion on their accession to the throne."