King of Assyria from 668 to 631 B.C. (though the latter date is disputed), under whom the Assyrian empire reached the height of its power in the ancient Near East. Numerous military victories allowed at least temporary control over most of Mesopotamia as well as Egypt, Elam, and southern Asia Minor. His library at Nineveh provides one of the most illuminative sources for Akkadian literature.
"I am Ashurbanipal, offspring of Assur and Belit, the oldest prince of the royal harem...in my reign there was fulness to overflowing, in my years there was plenteous abundance." (Rassam Cylinder)
We can generally divide the reign of Ashurbanipal into three distinct periods: the beginning of his reign (669-653), the uprising in Babylon (652-648), and the peaceful pax Assyrica lasting from 648 to 631.
Before Ashurbanipal's father, Esarhaddon, died in 669 while on campaign in Egypt, he had taken great care to ensure a smooth succession within the empire. Within living memory, the province of Babylon had been burned to the ground by Sennacherib, and Babylonian and nomadic Chaldean elements in the south were itching for independence. Esarhaddon's solution to the problem was to install Ashurbanipal as king of Assyria, and his brother, Shamash-shuma-ukin, as regent in Babylon. Oaths of loyalty were taken from all higher officials that they would support the arrangement.
The problems this caused will be all too apparent in a bit, but on the whole we can say that the transition of power took place quietly, and Ashurbanipal was free to continue his father's campaigns against Egypt by the following year. The Napatan rulers of the Nile Kingdom had been encouraging revolts in the Palestinian provinces for years. In the course of two campaigns in the early years of his reign, Ashurbanipal took Memphis and the cities of the politically fragmented Delta and installed puppet rulers in each. Though Assyrian control didn't last long - Psammetichus I re-united Egypt under his kingship in 656 - relations between the two states remained friendly.
On the whole, these foreign expeditions belong to the general trend of Assyria's warfare against its neighbours. The next major event of Ashurbanipal's reign gives the first clues to the end of the Neo-Assyrian empire, and require a bit of background. The key to the next 20 years is the exact nature of the relationship between Ashurbanipal and his brother in Babylon, and this is unfortunately vague and poorly understood. Shamash-shuma-ukin, while nominal regent in Babylonia, seems to have been wholly under his brother's control, unable to form treaties, engage in diplomacy, or even levy troops for defense. When, in 664, a combined army of Elamites and Aramaeans invaded Babylonia, it was left to Ashurbanipal to drive them out The same situation repeated itself in 653, and each time the campaign ended in the parade of flayed rebels around the empire.
"In these days Shamash-shuma-ukin, the faithless brother, whom I had treated well...forgot this kindness I had shown him and planned evil." (Rassam Cylinder)
Whatever the immediate causes of the revolt of 652-648 - Babylon's political impotence seems almost definitely to have been a major one - Shamash-shuma-ukin formed a loose federation of Chaldean tribes and Akkadian cities and declared his independence. The first year was spent in messenger-exchanges and diplomatic pussy-footing between the two chief factions; we aren't even sure exactly which cities revolted and which stayed loyal. Certainly, many switched sides more than once during the war. Open battle first began in 651, with Babylon's capture of Cutha, lead by Shamash-shuma-ukin himself. Assyrian forays were repeatedly driven back. By 650, however, Babylon began to lose serious ground. Ashurbanipal ordered the siege of the city that year. Economic texts attest to wretched conditions: plague runs rampant inside the city walls, while men sell children, wives, and land at absurdly low prices or in exchange for pathetic amounts of grain. Rebel cities began surrendering en masse in 649. Babylon fell, and was razed for the second time that century; a later tradition claims that Shamash-shuma-ukin, on the fall of his city, immolated himself on a great pyre. We hear no more of him.
"For the distance of one month and 25 days, I devastated the region of Elam. Salt and cress I sowed over them."
The following year was spent mopping up in Babylonia and abroad. Arabic and Chaldean rebels from the countryside and the southern Sealand had to be pacified first, while Ashurbanipal took his time sweeping ashes and corpses from the streets of Babylon. The one unforgivable supporter of the rebels was the Iranian Elamite king. A punitive expedition sacked and looted Susa and its environs; temples were burned, cemeteries dug up and the bones scattered, palaces reduced to ruins. Elam was destroyed as a political power. It's worth noting here that the sedition of Babylon, strengthening its age-old quest for independence, and the vacuum left by Elam's demise, soon filled by the kingdom of the Medes, are the main causes for Assyria's fall, 40 years later.
We know comparatively little about the last years of Ashurbanipal's reign, though it seems to have been peaceful. Babylon was slowly rebuilt (again), under the governor Kandalanu, while religious rites interrupted by the war resumed. Even Nineveh, the Assyrian capital, underwent great renovation, and the "succession palace" of Sennacherib was rebuilt (by the labour of captured enemy kings, the annals note). Though the famous Harran Inscription, a biography of the mother of Nabopolassar, puts Ashurbanipal's death in 627, the last record of his reign is dated to 631.
"I have read intricate tablets inscribed with obscure Sumerian or Akkadian...inscriptions on stone from before the Flood."
Ashurbanipal displayed a direct and intelligent interest in the personal management of his empire throughout his reign, leading campaigns and intervening in legal disputes. In effect, he proved the paradigm of the wise Mesopotamian king. While we don't have to assume that most kings were illiterate, he boasts of his education in the scribal arts to a degree unparalleled before him. In the great library of Nineveh we may even have first-hand proof of his ability to write: tablet labels written in an unpractised, clumsy hand stating "Ashurbanipal, king of Assyria".