To attain this end, missionaries, spread throughout all the oriental provinces, secretly taught the dogmas of the Ismailians, and laboured unceasingly to increase the number of their proselytes, and to inspire them with the spirit of revolt against the khalifs of Bagdad and the princes who acknowledged their authority. About the middle of the sixth century of the Hegira, one of these missionaries, named Hassan, son of Ali, having been gained over to the Ismailians, afterwards signalized himself by his zeal in the propagation of his adopted sect. This man, in other respects a good Musulman, being persuaded that the Fatimite khalif, Mostanssur, at that time reigning in Egypt, was the legitimate imam, resolved to repair to his court, deeming himself happy in being able to proffer his homage, and to revere in him the image and vice-gerent of the Deity. For this purpose, he left the northern provinces of Persia, where he was exercising the secret and dangerous functions of missionary, and proceeded to Egypt. His reputation had preceded him thither. The reception which he met with from the khalif, rendered it beyond the reach of doubt, that he would soon be called to the first offices. As usual, favour excited jealousy, and Hassan’s enemies soon found an opportunity of rendering him an object of the khalif’s suspicion. They even wished to have him arrested; but Mostanssur acceding reluctantly to their plans of revenge, they were satisfied with putting him on board a vessel bound for the northern coast of Africa. After some adventures, strongly tinged with the marvellous, Hassan returned to Syria, and thence passing through Aleppo, Bagdad, and Ispahan, he traversed the several provinces submitted to the Seljukide rule, everywhere performing his missionary functions, and omitting no means to effect the recognition of Mostanssur’s pontificate. After much travelling about, he at length established himself in the fortress of Alamut, situated in ancient Parthia, a short distance from Kaswin. The predictions of Hassan and some other missionaries, had multiplied the partisans of the Ismailites in these regions so considerably, that it was far from difficult to him, to compel the governor of that fortress, commanding in the of the Sultan Melekshah, to sell it to him for a moderate sum of money. Having become master of the place, he was able to maintain himself in its possession against all the sultan’s forces; and, by the insinuations of the missionaries, whom he sent into the environs, and by planned excursions, he subjected several places in the immediate neighbourhood, and erected for himself an independent sovereignty; in which, however, he only exercised his authority in the name of the imam, whose minister he acknowledged himself to be. The position of Alamut, situated as it is in the midst of a mountainous region, caused its prince to receive the title of _Sheikh al Jebal_ (_i. e._ _Sheikh_, or _Prince of the Mountains_); and the double