Yasmah-Adad is the son of the Amorite king Shamshi-Adad I, put on throne of Mari by his father after a successful military attack.

After Shamshi-Adad's death he manages to rule for only a short time before being ousted from power by Zimrilim.

His brother, Ishme-Dagan, rules at the same time in the city of Ekallatum.

The correspondence between the father and sons was found in the city of Mari and provides an interesting and at times humorous look into the dynamics of this family.