While the Shí‘ite missionaries (_du‘át_, sing. _dá‘í_) were actively engaged in canvassing for their party, which, as we have seen, recognised in ‘Alí and his descendants the only legitimate successors to Muḥammad, another branch of the Prophet's family--the ‘Abbásids--had entered the field with the secret intention of turning the labours of the ‘Alids to their own advantage. From their ancestor, ‘Abbás, the Prophet's uncle, they inherited those qualities of caution, duplicity, and worldly wisdom which ensure success in political intrigue. ‘Abdulláh, the son of ‘Abbás, devoted his talents to theology and interpretation of the Koran. He "passes for one of the strongest pillars of religious tradition; but, in the eyes of unprejudiced European research, he is only a crafty liar." His descendants "lived in deep retirement in Ḥumayma, a little place to the south of the Dead Sea, seemingly far withdrawn from the world, but which, on account of its proximity to the route by which Syrian pilgrims went to Mecca, afforded opportunities for communication with the remotest lands of Islam. From this centre they carried on the propaganda in their own behalf with the utmost skill. They had genius enough to see that the best soil for their efforts was the distant Khurásán--that is, the extensive north-eastern provinces of the old Persian Empire."[472] These countries were inhabited by a brave and high-spirited people who in consequence of their intolerable sufferings under the Umayyad tyranny, the devastation of their homes and the almost servile condition to which they had been reduced, were eager to join in any desperate enterprise that gave them hope of relief. Moreover, the Arabs in Khurásán were already to a large extent Persianised: they had Persian wives, wore trousers, drank wine, and kept the festivals of Nawrúz and Mihrgán; while the Persian language was generally understood and even spoken among them.[473] Many interesting details as to the methods of the ‘Abbásid emissaries will be found in Van Vloten's admirable work.[474] Starting from Kúfa, the residence of the Grand Master who directed the whole agitation, they went to and fro in the guise of merchants or pilgrims, cunningly adapting their doctrine to the intelligence of those whom they sought to enlist. Like the Shí‘ites, they canvassed for 'the House of the Prophet,' an ambiguous expression which might equally well be applied to the descendants of ‘Alí or of ‘Abbás, as is shown by the following table:--