o extend their sway in the western regions of
Africa, pursuing their conquests farther east. The Fatimite caliph Obaid
Allah and his son Abu'l Kasim cherished designs not only upon Egypt,
but even aimed at the destruction of the Abbasid caliphate, these plans
being so far successful as to leave the Fatimites in secure possession
of Alexandria, and more or less in power in Fayum.

The Fatimite caliphs had lofty and pretentious claims to the allegiance
of the Moslem world. They traced their descent from Fatima, a daughter
of the Prophet, whom Muhammed himself regarded as one of the four
perfect women. At the age of fifteen she married Ali, of whom she was
the only wife, and the partisans of Ali, as we have seen, disputed with
Omar the right to the leadership of Islam upon the Prophet's death.
Critics are not wanting who dispute the family origin of Obaid Allah,
but his claim appears to have been unhesitatingly admitted by his own
immediate followers. The Fatimite successes in the Mediterranean gave
them a substantial basis of political power, and doubtless this outward
and material success was more important to them than their claim to both
a physical and mythical descent from the founder of their religion.

Some accounts trace the descent of Obaid from Abd Allah ibn Maimun
el-Kaddah, the founder of the Ismailian sect, of which the Carmathians
were a branch. The Ismailians may be best regarded as one of the several
sects of Shiites, who originally were simply the partisans of Ali
against Omar, but by degrees they became identified as the upholders of
the Koran against the validity of the oral tradition, and when, later,
the whole of Persia espoused the cause of Ali, the Shiite belief
became tinged with all kinds of mysticism. The Ismailians believed, for
instance, in the coming of a Messiah, to whom they gave the name Mahdi,
and who would one day appear on earth to establish the reign of justice,
and revenge the wrongs done to the family of Ali. The Ismailians
regarded Obaid himself as the Mahdi, and they also believed in
incarnations of the "universal soul," which in former ages had appeared
as the Hebrew Prophets, but which to the Muhammedan manifested itself as
imans. The iman is properly the leader of public worship, but it is not
so much an office as a seership with mystical attributes. The Muhammedan
imans so far have numbered eleven, the twelfth, and greatest (El-Mahdi),
being yet to come. The Ismailians also intro