Išme-Dagān II, son of Šamši-Adad II, ruled Assyria for sixteen years (during the so-called Assyrian 'Dark Age'). According to the Assyrian King List [/riao/kinglists/assyriankinglist/assyriankinglist/index.html#BelubaniDynasty] (AKL), two of his sons sat on the Assyrian throne: Šamši-Adad III and Aššur-nārārī I. No inscriptions of Išme-Dagān II have yet been discovered.
Yehonatan Hershkovitz
Yehonatan Hershkovitz, 'Išme-Dagān II', RIA 1: Inscriptions from the Origins of Assyria to Arik-dīn-ili, The RIA Project, 2023 [http://oracc.org/oldassyrianperiod/belubanidynasty/ishmedaganii/]