Ashurbanipal

Ashurbanipal became king of the Neo-Assyrian Empire in 669 BC after his father Esarhaddon bypassed an older son and named him heir around 673, installing that brother as a monitored vassal in Babylonia. He spent his early years crushing rebellions in Egypt, then turned against Elam - an ancient enemy - defeating it in campaigns in 665, 653, and 647-646 in what has been described as genocide. In 652 his brother Shamash-shum-ukin rebelled and assembled a coalition of enemies; Ashurbanipal besieged Babylon and his brother died in 648. Between the wars he poured resources into the Library of Ashurbanipal, a collection perhaps exceeding 100,000 texts that would not be surpassed until Alexandria centuries later; over 30,000 cuneiform tablets survived as a cornerstone source on Mesopotamian language, religion, and science. His campaigns reached farther than any Assyrian king before him, but Egypt slipped away, Arabia drained resources without lasting gain, and the sack of Babylon may have seeded the empire that rose five years after his death in 631. The Greeks garbled him into Sardanapalus, a decadent last king - a legend that stuck longer than the truth.