The Abbasid caliphs were always...
The Abbasid caliphs were always, by way of oppression and over-indulgence in pleasure seeking, intending to wipe out the Hashemites so that they would put the progeny of ‘Ali (as), away from the political arena, and curtail their power over the Islamic states. To achieve this malicious purpose, they encouraged and sponsored some of the Ja‘fari school disciples to establish another school against the Ja‘fari School.
In this way, different schools of Hanafites, Hanbalites, Shafi‘ites, and Malikites were founded, each with its own juristic method. The governments of the time and the ones that followed them supported these schools in order to achieve power and considered their discrepancies to the benefits of their own ends.
Toward the end of Mansur Dawaniqi's caliphate, coinciding with the early years of the Imamate of Imam Musa al-Kazim (as), “many of the rebellious Sayyids who were typically from among the scholars and the brave and pious followers of the Holy Prophet (S)'s household and were closely related with the Imams (as), were killed as martyrs.
These noble figures would rise up to fend off oppression and to disseminate the charter of justice and to enjoin right and forbid wrong, and would finally give their lives for the essentials of the Islamic teachings; thus awakening the sleeping souls.
They would sacrifice their own souls and let their own bloodshed in the Islamic cities and towns to keep the call to prayer ( adhan ) reverberating from the minarets of the mosques.”[^1] In Medina, the functionaries of Mahdi ‘Abbasi, the son of Mansur Dawaniqi took up the same vile behavior as that of the evil dynasty of the Umayyad, and mistreated the progeny of Imam ‘Ali (as) as harshly as they could.
The tragic event of Fakh (a place about 7 kms from Mecca on the way to Medina) took place in the era of Hadi ‘Abbasi. The event started when Husayn b. ‘Ali b. ‘Abid, who was an honorable descendant of Imam al-Hasan (as) and a noble scholarly chief of a clan in Medina, revolted with the help of a number of the Sayyids and Shi‘as against the cruelties of ‘Abd al-‘Aziz ‘Umari, who was dominating Medina, and with utmost bravery killed many of the opponents in the land of Fakh.
Eventually, the brutal enemies besieged this brave Sayyid and murdered him and a number of his companions and captured some others. Mas‘udi wrote: “The bodies remained in the desert were eaten up by beasts of prey.” The wickedness of the Abbasid was not restricted to this event.