al-Ma'mun's repudiation of the Almohad creed

In 626 AH the caliph al-Ma'mun ibn al-Mansur entered Marrakesh and announced that he was abandoning the mission (da'wa) of the Almohads. Ibn Khaldun reports that he summoned the elders of the Almohads, enumerated their deeds to them, and killed a hundred of their notables. ¹

• Erasing the name of the Mahdi Ibn Tumart from the coinage and the sermon, and denouncing him in the call to prayer in the Berber language.
• Adding the phrase "asbaha wa-l-hamdu lillah" ("morning has come, and praise be to God") to the dawn call to prayer.
• Permission for the Christians who had come with him to build a church in Marrakesh.
• Expelling the Almohads from al-Andalus. Ibn Khaldun says that the common people killed them in every region.

¹

The source says that the forms of the mission were restored only after him, through his son al-Rashid, on condition of the elders of Tinmallal. ¹

The Gregorian date is derived. It needs an additional source.