 At the age of 16, Shapur II led an expedition against the Arabs; primarily campaigning against the Iyad tribe in Asoristan and thereafter he crossed the Persian Gulf, reaching al-Khatt, modern Qatif, or present eastern Saudi Arabia.He then attacked the Banu Tamim in the Al Hajar Mountains.Shapur II reportedly killed a large number of the Arab population and destroyed their water supplies by stopping their wells with sand.