Shalmaneser I

This king strengthened Assyrian control over the former kingdom of Mitanni by replacing the client-king with a directly appointed Assyrian governor, or sukkallu rabu (Kuhrt pg. 354). He also tightened control of the area around the Balikh valley by setting up governors within fortified manors in several sites like Tell Sabi Abyad, Tell Fekheriye, and Dur-Katlimmu (ibid). Along with this went a notable victory over the Hittites in the upper Euphrates, which gave him control over the small state of Nihriya (Kuhrt pg. 355).