Ismail was born to Muhammad al-Atrash. The latter was deaf, hence the family's name, al-Atrash, which means the deaf in Arabic. Ismail's grandfather, also named Muhammad, migrated to the Hauran region south of Damascus in the early 19th century. Ismail was first mentioned in the historical record in the early 1840s when he joined Shibli al-Aryan, the Druze leader of Wadi al-Taym, in his efforts to intervene on behalf of the Druze of Mount Lebanon against the Maronites. Ismail gained a repute among the Druze for his battlefield performance and following al-Aryan's death, succeeded him as the virtual military chieftain of the Druze.