The Tinmel massacre — end of Banu Abd al-Mu'min

Ibn Khaldun relates in "al-Ibar" that in 674 AH the remnants of the Banu Abd al-Mu'min took refuge on the mountain of Tinmal, the stronghold of the Almohad call. Muhammad ibn Ali ibn Mahalla, agent of the sultan Abu Yusuf over the lands of Marrakesh, stormed it. ¹

In the battle their caliph, the weak one, was killed, and their vizier Ibn Atush. Those seized in Marrakesh had their necks struck. ¹

Ibn Khaldun says that the tombs of the Banu Abd al-Mu'min's caliphs were scattered, and the heads of Yusuf and his son Ya'qub al-Mansur were cut off after their bodies had been dug up. He attributes this to Abu Ali al-Miliyani. He says the sultan disapproved of the act, then overlooked it. ¹

Ibn Khaldun says that the line of the Banu Abd al-Mu'min was cut off by this. That is the narrator's judgement, not the museum's; the report comes from a single source and needs an additional source.