cure struggles between rapidly
melting groups of adherents. Its chief features are: the founding of
Moulay Idriss and Fez, and the building of the mosques of El Andalous
and Kairouiyin at Fez for the two groups of refugees from Tunisia and
Spain. Meanwhile the Caliphate of Cordova had reached the height of its
power, while that of the Fatimites extended from the Nile to western
Morocco, and the little Idrissite empire, pulverized under the weight of
these expanding powers, became once more a dust of disintegrated tribes.

It was only in the eleventh century that the dust again conglomerated.
Two Arab tribes from the desert of the Hedjaz, suddenly driven westward
by the Fatimites, entered Morocco, not with a small military
expedition, as the Arabs had hitherto done, but with a horde of
emigrants reckoned as high as 200,000 families; and this first
colonizing expedition was doubtless succeeded by others.

To strengthen their hold in Morocco the Arab colonists embraced the
dynastic feuds of the Berbers. They inaugurated a period of general
havoc which destroyed what little prosperity had survived the break-up
of the Idrissite rule, and many Berber tribes took refuge in the
mountains; but others remained and were merged with the invaders,
reforming into new tribes of mixed Berber and Arab blood. This invasion
was almost purely destructive, it marks one of the most desolate periods
in the progress of the "wasteful Empire" of Moghreb.

IV

ALMORAVIDS AND ALMOHADS

While the Hilalian Arabs were conquering and destroying northern Morocco
another but more fruitful invasion was upon her from the south. The
Almoravids, one of the tribes of Veiled Men of the south, driven by the
usual mixture of religious zeal and lust of booty, set out to invade the
rich black kingdoms north of the Sahara. Thence they crossed the Atlas
under their great chief, Youssef-ben-Tachfin, and founded the city of
Marrakech in 1062. From Marrakech they advanced on Idrissite Fez and the
valley of the Moulouya. Fez rose against her conquerors, and Youssef put
all the male inhabitants to death. By 1084 he was master of Tangier and
the Rif, and his rule stretched as far west as Tlemcen, Oran and finally
Algiers.

His ambition drove him across the straits to Spain, where he conquered
one Moslem prince after another and wiped out the luxurious civilization
of Moorish Andalusia. In 1086, at Zallarca, Youssef gave battle to
Alphonso VI of Castile and Leo