Al-Sahel's Dynasty and their actions during the Abbasid caliphate period

After the fall of the Barmakids, the Islamic Empire started to weaken, and the partitioning of Abbasid caliphate began since Harun al-Rashid. After a while, during a speech, Harun al-Rashid mentioned all the consequences which were caused by the absence of Barmakids dynasty. By slaughtering of the Barmakids, Persians’ influence decreased in the Abbasid state apparatus for a short period. However, during the struggle between Amin and Ma'mun which resulted to victory of Ma'mun over Amin with leadership of his Iranian prominent commander-in-chief, Tahir Dhul-Yamīnayn and the reinstating of Ma’mun to power again by the Iranian minister, Abu l-Abbas al-Fadl ibn Sahl, Persians regained their influence and power in the Abbasid
caliphate and the ruling of Islamic lands once again.