Ashurnasirpal II succeeded his father, Tukulti-Ninurta II, in 883 BC. During his reign he embarked on a vast program of expansion, first conquering the peoples to the north in Asia Minor as far as Nairi and exacting tribute from Phrygia, then invading Aram (modern Syria) conquering the Aramaeans and neo Hittites between the Khabur and the Euphrates Rivers. His harshness prompted a revolt that he crushed decisively in a pitched, two-day battle. According to his monument inscription, while recalling this massacre he says:
The palaces, temples and other buildings raised by him bear witness to a considerable development of wealth and art. He was renowned for his brutality, using enslaved captives to build a new Assyrian capital at Kalhu (Nimrud) in Mesopotamia where he built many impressive monuments. He was also a shrewd administrator, who realized that he could gain greater control over his empire by installing Assyrian governors, rather than depending on local client rulers paying tribute.
Like previous Assyrian monarchs Ashurnasirpal campaigned along the Euphrates against Aramaeans and in the Diyala against Babylon. Ashurnasirpal II's brutal treatment of rebels ensured that even when his army was not present, there would not be further revolts. Further revolts would see the local monarch replaced with a governor loyal only to the Assyrian monarchy. Leading his army, which was typically composed of infantry (including auxiliaries and foreigners), heavy & light cavalry and chariots, Ashurnasirpal conquered the Hittites and Aramaean states of northern Syria.