MOKANNA (al-Moqanna', the Veiled)  , the name given to Hakim, or `Ata, a man of unknown parentage, originally a fuller in Merv, who posed as an incarnation of Deity, and headed a revolt in Khorasan against the caliph Mandi . For about three years he sustained himself in the field against" the troops of the caliph and for two years longer in his fortress of Sanam; then, reduced to straits in 779, he and his followers took poison and set fire to the fortress . Much is related to his magical arts, especially of a moonlike light visible for an enormous distance which he made to rise from a pit near Nakhshab . He is the hero of the first part of Moore's Lalla Rookh .