Although his father counted Ishme-Dagan I as politically astute and a capable soldier, commending him as he berated Yasmah-Adad in their letters, Ishme-Dagan I was not able to hold his father's empire for long after his father died. Ishme-Dagan I eventually lost most of his domain, and was reduced to holding Ashur and Ekallatum, despite waging several counter offensives to try to regain the upper Khabur area. The year-name of the fifth year of Ibalpiel II's reign (indicating some reverence to Shamshi-Adad I at his passing) suggests that Eshnunna had become subservient to the Ekallatum. Ishme-Dagan I wrote a letter to his brother, after Ishme-Dagan I assumes their father's throne and the rule of all of Upper Mesopotamia, that he:
