Nubia and from Cyprus to Iran), he installed his eldest son Shamash-shum-ukin as a subject king in Babylon, and his youngest, the highly educated Ashurbanipal (669–627 BC), in the more senior position as king of Assyria and overlord of Shamash-shum-ukin. Babylonian revolt Despite being an Assyrian himself, Shamash-shum-ukin, after decades subject to his brother Ashurbanipal, declared that the city of Babylon (and not the Assyrian city of Nineveh) should be the seat of the immense empire. He raised a major revolt against his brother, Ashurbanipal. He led a powerful coalition of peoples also resentful of Assyrian subjugation and rule, including Elam, the Persians, Medes, the Babylonians, Chaldeans and Suteans of southern Mesopotamia, the Arameans of the Levant and southwest Mesopotamia, the Arabs and Dilmunites of the Arabian Peninsula and the Canaanites-Phoenicians. After a bitter struggle Babylon was sacked and its allies vanquished, Shamash-shum-ukim being killed in the process. Elam was destroyed once and for all, and the Babylonians, Persians, Chaldeans, Arabs, Medes, Elamites, Arameans, Suteans and Canaanites were violently subjugated, with Assyrian troops exacting savage revenge on the rebelling peoples. An Assyrian governor named Kandalanu was placed on the throne to rule on behalf of the Assyrian king. Upon Ashurbanipal's death in 627 BC, his son Ashur-etil-ilani (627–623 BC) became ruler of Babylon and Assyria. However, Assyria soon descended into a series of brutal internal civil wars which were to cause its downfall. Ashur-etil-ilani was deposed by one of his own generals, named Sin-shumu-lishir in 623 BC, who also set himself up as king in Babylon. After only one year on the throne amidst continual civil war, Sinsharishkun (622–612 BC) ousted him as ruler of Assyria and Babylonia in 622 BC. However, he too was beset by constant unremitting civil war in the Assyrian heartland. Babylonia took advantage of this and rebelled under Nabopolassar, a previously unknown malka (chieftain) of the Chaldeans, who had settled in southeastern Mesopotamia by c. 850 BC. It was during the reign of Sin-shar-ishkun that Assyria's vast empire began to unravel, and many of its former subject peoples ceased to pay tribute, most significantly for the Assyrians; the Babylonians, Chaldeans, Medes, Persians, Scythians, Arameans and Cimmerians. Neo-Babylonian Empire (Chaldean Empire) In 620 BC Nabopolassar seized control over much of Babylonia with the support of most of the inhabitants, with only the city of Nippur and some northern regions showing any loyalty to the beleaguered Assyrian