Yasmah-Adad (Yasmah-Addu, Yasmakh-Adad, Ismah-Adad, Iasmakh-Adad) was the younger son of the Amorite king of Upper Mesopotamia, Shamshi-Adad I. He was put on throne of Mari by his father after a successful military attack following the assassination of Yahdun-Lim of Mari in 1795 B.C.E. He was responsible for the southwestern section of his father's kingdom (of which Mari was the capital) including the Balikh River, Habur River, and Euphrates River. Yasmah-Adad's administrative district bordered the state of Yamkhad and the Syrian steppe (inhabited by semi-nomadic peoples). His father controlled the northern part of the kingdom from Shubat-Enlil, and his older brother, Ishme-Dagan, ruled over the southeast area from Ekallatum. Yasmah-Adad's leadership of Mari and the surrounding districts around the Euphrates ended when his father died, and the Amorite Zimri-Lim and his army chased him out of Mari and took his throne in 1776 B.C. The sources do not fully agree, but state that he was either chased out of his borders or killed before being allowed to flee.