The Osseiran family traces its Shiite origins to what is now Iraq and there to the tribe of the Bani Asad, which fought alongside Hussein - the son of Ali and grandson of the prophet Mohammed, at Karbala in 680. After their defeat the survivors suffered persectuion and after an unknown period of time one of the tribal members - Haidar - reportedly fled to Baalbek, where he had two sons: Ali and Osseiran. According to the family's historiography, the latter settled in Sidon/Saida. Historians have established that the Osseirans rose to prominence and power as grain merchants in Sidon and the Jabal Amel region of modern-day Southern Lebanon soon after the Ottoman Empire assumed control over the area in 1516:""Having arrived some time in the sixteenth or seventeenth century and built up significant wealth from mercantile activities, they were eventually appointed consuls for Iran. As consuls they, and their employees, were exempt from Ottoman military service and were levied a lower tax on their goods. This allowed them to build their wealth more rapidly and to gather a greater supporter base in Saida and Zahrani (where they owned land) due to the privileges accorded their employees.""