In Cairo the Fatimid caliph reacted by inviting the Bani Hilal
and Bani Salim, beduin tribes from Arabia known collectively as
the Hilalians, to migrate to the Maghrib and punish his rebellious
vassals, the Zirids. The Arab nomads spread across the region,
in the words of the historian Ibn Khaldun, like a "swarm of locusts,"
impoverishing it, destroying towns, and dramatically altering
the face and culture of the countryside.
The Hilalian impact on Cyrenaica and Tripolitania was devastating
in both economic and demographic terms. Tripoli was sacked, and
what little remained of urban life in once-great cities like Cyrene
was snuffed out, leaving only ruins. Over a long period of time,
Arabs displaced Berbers (many of whom joined the Hilalians) from
their traditional lands and converted farmland to pasturage. Land
was neglected, and the steppe was allowed to intrude into the
The number of Hilalians who moved westward out of Egypt has been
estimated as high as 200,000 families. The Bani Salim seem to
have stopped in Libya, while the Bani Hilal continued across the
Maghrib until they reached the Atlantic coast of Morocco and completed
the Arabization of the region, imposing their social organization,
values, and language on it. The process was particularly thorough
in Cyrenaica, which is said to be more Arab than any place in
the Arab world except for the interior of Arabia.
The Norman rulers of southern Italy took advantage of the Zirids'
distress in North Africa to invade Sicily in 1060 and bring it
back under Christian control. By 1150 the Normans held a string
of ports and fortresses along the coast between Tunis and Tripoli,
but their interests in North Africa were commercial rather than
political, and no effort was made to extend the conquest inland.
Data as of 1987