The first Fatimite caliph, though without experience, was so vigorous a ruler that he could dispense with the dangerous support of his discoverer. He held the throne for a quarter of a century and established his authority, more or less continuously, over the Arab and Berber tribes and settled cities from the frontier of Egypt to the province of Fez (Fas) in Morocco, received the allegiance of the Mahometan governor of Sicily, and twice despatched expeditions into Egypt, which he would probably have permanently conquered if he had not been hampered by perpetual insurrections in Barbary. Distant governors, and often whole tribes of Berbers, were constantly in revolt, and the disastrous famine of 928-929, coupled with the Asiatic plague which his troops had brought back with them from Egypt, led to general disturbances and insurrections which fully occupied the later years of his reign. The western provinces, from Tahart and Nakur to Fez and beyond, frequently threw off all show of allegiance. His authority was founded more on fear than on religious enthusiasm, though zeal for the Alide cause had its share in his original success. The new "Eastern doctrines," as they were called, were enforced at the sword's point, and frightful examples were made of those who ventured to tread in the old paths. Nor were the freethinkers of the large towns, who shared the missionary's esoteric principles, encouraged; for outwardly, at least, the Mahdi was strictly a Moslem. When people at Kayrawan began to put in practice the missionary's advanced theories, to scoff at all the rules of Islam, to indulge in free love, pig's flesh, and wine, they were sternly brought to order. The mysterious powers expected of a mahdi were sedulously rumored among the credulous Berbers, though no miracles were actually exhibited; and the obedience of the conquered provinces was secured by horrible outrages and atrocities, of which the terrified people dared not provoke a repetition at the hands of the Mahdi's savage generals.