Book excerpt: It is an established historical fact that both sides of the Straits of Gibraltar formed a cultural unity in many different periods. After the military success of Mûs_ ib Nusayr, Islam broght unity to Arabs and many Berber tribes in the Maghrib, but the struggle for independence and the adoption of the eastern Khârijî doctrine always caused struggles. It is a well known fact that the contingent of Berbers among the Muslims of al-Andalus outnumbered considerably the inhabitants from Arab origin. After the decline and collapse of the Umayyads and Hammûdids in al-Andalus, various Berger dynasties seized their power and founded many different kingdoms (Taifas, from Arabic mulûk al-tawâ'if). Arab Andalusi culture flourished, which can be demonstrated by the fact that Arabic became the most important language of the Iberian Peninsula under Muslim rule. On the other hand, large numbers of Andalusis emigrated to the Maghrib in many different periods. Already in the first centuries of Islamic spain, many Andalusis settled in North Africa. These Andalusis fled as a consequence of the drought, or were expelled for having collaborated against the regime or were forced to leave the Peninsula by the Christian Reconquista. Mutual migrations and political unity led to the exchange of many cultural phenomena between the two sides of the Straits. This fourth issue of Orientations focuses on some aspects of the 'cultural transfer between al-Andalus and North Africa, ' and particularly deals with some aspects of Poetry, Politics and Polemics from the eleventeenth to the seventeenth century.