Juhayman ibn Muhammad ibn Sayf al-Otaybi was a Saudi religious dissident and ex-soldier who led the Ikhwan during their Grand Mosque seizure in 1979. He and his followers besieged and took over the Grand Mosque of Mecca on 20 November 1979 and held it for two weeks. During this time, he called for an uprising against the House of Saud and also reportedly proclaimed that the Mahdi had arrived in the form of one of the Ikhwan's leading officials; al-Otaybi's insurgency ended with Saudi authorities capturing the surviving militants and publicly executing them all, including al-Otaybi.