He employed the same tactics as his predecessors and appears to have utilized his forces rationally and strategically, fighting entirely in-line with traditional Assyrian warfare.
As a consequence of Assyria's violent downfall,[7] the period from a few years before the death of Ashurbanipal to the Fall of Nineveh in 612 BC suffers from a distinct lack of surviving sources.
[8] Although Ashurbanipal's final year is often repeated as 627 BC[9][10], this follows an inscription at Harran made by the mother of the Neo-Babylonian king Nabonidus nearly a century later.
[7] Though Babylonia in the south had also once been a large kingdom, it had typically been weaker than its northern neighbor due to internal divisions and the lack of a well-organized army.
Though old native Babylonians ruled most of the cities, such as Kish, Ur, Uruk, Borsippa, Nippur, and Babylon itself, the Chaldean tribes, led by chieftains who often squabbled with each other, dominated most of the southernmost land.
Though Babylon was respected as the well-spring of civilization, it was expected to remain passive in political matters, something that Assyria's "Babylonian bride" repeatedly refused to be.
Despite the enormous effort spent in keeping the region, Babylonia was seen as too important economically and strategically to allow to secede, but no matter what the Assyrians attempted, rebellion and civil war was the inevitable result each time.
[26] Sîn-šumu-līšir had been a key figure in Assyria during Aššur-etil-ilāni's reign, putting down several revolts and possibly being the de facto leader of the country.
The possibility that a eunuch, normally trusted due to their perceived lack of political ambition, would do so had never been entertained prior to Sîn-šumu-līšir's attempt.
[29][30] Sîn-šumu-līšir successfully seized control of some cities in northern Babylonia, including Nippur and Babylon itself and would rule there for three months before Sîn-šar-iškun defeated him.
An official or general called Nabopolassar, possibly using the political instability caused by the previous revolt[26] and the ongoing interregnum in the south,[31] assaulted both Nippur and Babylon.
[35] In the aftermath of the failed Assyrian counterattack, Nabopolassar was formally crowned king of Babylon on November 22/23 626 BC, restoring Babylonia as an independent kingdom.
[38] Though he had successfully driven out the Assyrian army, pro-Assyrian factions still existed in some Babylonian cities, for instance Ur and Nippur, by 617 BC, making Nabopolassar's full consolidation of control in the south slow.
[39] The fighting in Babylonia in the last stages of the localized conflict turned conditions so desperate in some places that parents sold their children into slavery to avoid them starving to death.
Psamtik had over the last few years campaigned to establish dominance over the small city-states of the Levant and it was in his interests that Assyria survived as a buffer state between his own empire and those of the Babylonians and Medes in the east.
[38] A joint Egyptian-Assyrian campaign to capture the city of Gablinu was undertaken in October of 616 BC, but ended in failure after which the Egyptian allies kept to the west of the Euphrates, only offering limited support.
[42] In May 615 BC, Nabopolassar and the Babylonians assaulted Assur, the ceremonial and religious center of Assyria and the Assyrian Empire's southernmost remaining city.
[7][42] Though the conflict had shifted to Assyria becoming the defender, the war was at this point still being fought according to standard Mesopotamian practice, with attacks, counterattacks and retreats and neither side having the confidence or means to force a decisive confrontation.
[41] Although there are plenty of earlier sources discussing Assyro-Median relations, none are preserved from the period leading up to Cyaxares's invasion and as such, the political context and reasons for the sudden attack are not known.
Even the Babylonian chronicles, hostile to Assyria, speak of the Medes as unnecessarily brutal, stating that they "inflicted a terrible defeat on a great people, pillaged and looted them and robbed them".
[43] In an attempt to keep the enemies out of Assyria, Sîn-šar-iškun went on the offensive in 613 BC, attacking Nabopolassar's forces in the middle Euphrates, occupied at the time with suppressing an Assyrian-supported rebellion of a local tribe.
[2] Around this time, Sîn-šar-iškun, apparently finally recognizing the disaster that was about to befall his kingdom, sent a letter to Nabopolassar, attempting to broker peace.
[46] In April or May 612 BC, at the start of Nabopolassar's fourteenth year as king of Babylon, the combined Medo-Babylonian army marched on Nineveh.
[2] Sîn-šar-iškun rallied his forces to make a final stand at the capital but stood little chance at defending it on account of the city's massive size.
[50] Sîn-šar-iškun was succeeded by another Assyrian king, Aššur-uballiṭ II, possibly his son and probably the same person as a crown prince mentioned in inscriptions at Nineveh from 626 and 623 BC.
[48] Because Assur had been destroyed, Aššur-uballiṭ could not undergo the traditional coronation of the Assyrian monarchs and could thus not be invested with the kingship by the god Ashur and because of this, inscriptions from his brief reign indicate that he was viewed as the legitimate ruler by his subjects, but still with the title of crown prince and not king.
Your people are scattered on the mountains with no one to gather them.Although it has been a commonly circulated idea that one of the primary reasons that led to the fall of the Neo-Assyrian Empire was a civil war between Aššur-etil-ilāni and Sîn-šar-iškun over the throne which weakened Assyria, there is no contemporary text which suggests that this is true.
Nabopolassar's revolt was the last in a long line of Babylonian uprisings against the Assyrians and Sîn-šar-iškun's failure to stop it, despite trying for years, doomed his kingdom.
Using alternate tactics probably never occurred to him and with an Assyrian mindset considered, he appears to have been a capable military leader who deployed his forces rationally and strategically.