Since 311, as we have seen, the Qarmatians had occupied Basra. In 317 they had spread down into the Hijaz, and on the 8th of the month of the pilgrimage in that year the pilgrims who had come up to Mecca were attacked by them. The Sherif of Mecca, many of his attendants, and many of the pilgrims, were killed: the sacred spring of Zamzam was choked up with the bodies of the slain which were tumbled in: the door of the “House of God” was broken open, the veil which covered the House was torn down, and the sacred black stone was removed from the Kaʿaba and carried away to the Qarmatian headquarters at Hajar. Never in the history of Islam has there been sacrilege at all comparable to this, and never before had the Qarmatians advertised so boldly their contempt for the Muslim religion. Begkem, the Emir of Baghdad, offered them a reward of 50,000 dinars to restore the sacred stone, but the offer was refused. According to Ibn Athir, quoted by Ibn Khallikan (i. 427, etc.) the Mahdi then wrote to them from Kairawan: “By what you have done you have justified the charge of infidelity brought against our sect, and the title of ‘impious’ given to the missionaries acting for our dynasty; if you restore not what you have taken from the people of Mecca, the pilgrims and others, if you replace not the Black Stone and the veil of the Kaʿaba, we shall renounce you in this world and the next.” This letter was more effectual than Begkem’s proffered reward, and the Qarmatians restored the Black Stone with the statement, “We took it by order, and by order we return it.” It was restored either in Dhu l-Kaada or Dhu l-Hijja of 339. Of the year there seems no question, and Ibn Khallikan points out that the Mahdi died in 322. He suggests, therefore, that the letter and the Qarmatian reply were fabrications, presumably for the purpose of throwing the odium of sacrilege on the Mahdi. But it is not necessary to suppose that the Black Stone was returned immediately in response to the Mahdi’s request. A more likely interpretation is given by Macdonald, who accepts the letter as genuine and comments: “When an enormous ransom was offered for the stone they (_i.e._, the Qarmatians) declined—they had orders not to send it back. Everyone understood that the orders were from Africa. So ʿUbayd Allah found it advisable to address them in a public letter, exhorting them to be better Muslims. The writing and reading of this letter must have been accompanied by mirth, at any rate no attention was paid to it by the Qarmatians. It was not till the time of the third Fatimid Khalifa that they were permitted to do business with that stone” (Macdonald: _Muslim Theology_, pp. 46-47). This suggests a plausible explanation, that the letter was sent by the Mahdi, but was only intended to disclaim any responsibility for the taking of the stone on his part; that it was not intended to be heeded, and was not taken seriously, the stone being detained until long after the Mahdi’s death.