The Assyrian Empire originated in the early 2nd millennium BC, succeeding the Akkadian Kingdom of the late 3rd millennium BC. Assyria did not become a powerful military state until the early 1st millennium BC, when Ashurnasirpal II's conquests reasserted Assyria's hegemony in the Near East, nor was it a true empire until the reforms of Tiglath-Pileser III in the mid-8th century BC. The Assyrian empire has at times been described as the first military power in history. This article deals with the forces of the Assyrians in the above described times.
In 911 B.C., the Assyrian state was ruled by Adad-nirari II and was in a poor state - trade routes were under foreign control and her territories in Babylon and other former vassal states were out of their hands. Adad nirari II changed all of this with aggressive campaigning against his opponents. His son was later succeeded by one of the most successful military Kings of Assyria, Ashurnasirpal II.
Ashurnasirpal II is credited for utilizing sound strategy in his wars of conquest. Whilst aiming to secure defensible frontiers, he would launch raids further inland against his opponents as a means of securing economic benefit, as he did when campaigning in the Levant. The result meant that the economic prosperity of the region would fuel the Assyrian war machine.
Ashurnasirpal II was succeeded by Shalmaneser III. Although he campaigned for 31 years of his 35 year reign, he failed to achieve or equal the conquests of his predecessor, and his death led to another period of weakness in Assyrian rule.
Assyria would later recover under Tiglath Pileser III whose reforms once again made Assyria the most powerful force in the Near East, and transformed her into a fully fledged empire - the first of its kind. Later Kings under Shalmaneser V, Sargon II and Sennacherib would see further Assyrian offensives, although these were designed not so much for conquest but to destroy the enemies ability to undermine Assyrian power. As such, costly battles raged taking tolls on Assyrian manpower. Esarhaddon succeeded in taking lower Egypt and his successor, Ashurbanipal, took the southern upper half of Egypt.
However, by the end of the Ashurbanipal's reign it appears that the Assyrian Empire was falling into another period of weakness, one from which she would not escape. It appears that years of costly battles followed by constant (and almost unstoppable) rebellions meant that it was a matter of time before Assyria ran out of troops. The loss of the outer regions meant that foreign troops were gone too. By 605 B.C., Independent Political Assyrian records vanish from history and the Assyrians lose their independence forever.