 By mid-871 'Ali ibn Aban was encamped in the district of Jubba, while Yahya was stationed on the Ma'qil Canal, in the vicinity of Basra.In an effort to combat the Zanj, the Abbasid central government in Samarra had dispatched a number of commanders, such as Ju'lan al-Turki, Sa'id al-Hajib, and Ibrahim ibn Sima al-Turki to lower Iraq and al-Ahwaz.These men were sometimes able to score a military victory against the rebels, but more often they suffered defeat, and in any case they were unable to effectively hinder the operations of the Zanj throughout the region.