Nabopolassar (/ˌnæboʊpəˈlæsər/; cuneiform: 𒀭𒀝𒌉𒍑𒌶dAG.IBILA.URU3Akkadian: Nabû-apla-uṣur; c. 658 BC – 605 BC) was a Chaldean king of Babylonia and a central figure in the fall of the Neo-Assyrian Empire. The death of Assyrian king Ashurbanipal in 631 BC resulted in political instability. In 626 BC, a native dynasty arose under Nabopolassar. He made Babylon his capital and ruled over Babylonia for a period of about twenty years (626–605 BC). He is credited with founding the Neo-Babylonian Empire. By 616 BC, Nabopolassar had united the entire area under his rule.
Nabopolassar formed an alliance with Cyaxares of the Medes to confront the Assyrians and their Egyptian allies. By 615 BC he had seized Nippur. He then led his forces to assist the Medes besieging the city of Ashur, but the Babylonian army did not reach the battlefield until after the city had fallen.
Assyria, weakened by internal strife and ineffectual rule, was unable to resist the Babylonians and the Medes, who united to sack the Assyrian capital of Nineveh in 612 BC. Following a prolonged siege at the Battle of Nineveh, Nabopolassar took control of the city. Ashur-uballit II was a member of the Assyrian royal family and a tartan (general) in the army. He became king after Sin-shar-ishkun, who may have been his brother, and who probably died during the fall of Nineveh.
Ashur-uballit II rallied his troops at the city of Harran in northern Syria. The following year the Babylonians plundered the region of Harran, and in 610 BC, Nabopolassar captured the city.
In the spring of 609 BC, Necho II of Egypt led a sizable force to help the Assyrians. At the head of a large army, consisting mainly of mercenaries, Necho took the coastal Via Maris into Syria, supported by his Mediterranean fleet along the shore. He prepared to cross the ridge of hills which shuts in on the south the great Jezreel Valley, but he found his passage blocked by the army of the Kingdom of Judah. Their king, Josiah, sided with the Babylonians and attempted to block his advance at the Battle of Megiddo, where a fierce battle was fought and Josiah was killed. Necho continued on and joining forces with Ashur-uballit, they crossed the Euphrates and laid siege to Harran. Failing to capture Harran, they retreated to northern Syria.
In 605 BC, Nabopolassar's son, crown prince Nebuchadnezzar fought Necho and the remnants of the Assyrian army at the Battle of Carchemish. Within months of his abdication in 605 BC, Nabopolassar died of natural causes at about 53 years of age, and Nebuchadnezzar II hurried to Babylon to secure the throne.
During Nabopolassar's reign, there was a boom of Neo-Babylonian building projects that would continue through the reign of his son, Nebuchadnezzar II. Temples and ziggurats were repaired or rebuilt in almost all the old dynastic cities, while Babylon itself was enlarged and surrounded by a double enceinte, or line of fortification, consisting of towered and moated fortress walls. The first mention of Nebuchadnezzar II comes from the records of Nabopolassar, saying he was a laborer in the restoration of the temple of Marduk.
A cylinder found in 1921 in Baghdad, Iraq is attributed to Nabopolassar. He is described therein as extremely pious, and that he "sought out the temples... and the complete performance of their rites." He attributes his success to Shazu (one of the names associated with Marduk). Throughout the inscription, Nabopolassar describes some of his greatest military conquests and submits himself to Marduk and other deities.