The golden age of al-Andalus peaked during the late 10th century, when al-Mansur, an advisor at the Umayyad court, became the regent and effective ruler of al-Andalus. His dominance had, however, effectively eroded the perceived power of the emir and on his death in 1002 the rulers of a mosaic of independent principalities clamoured for power. A disastrous civil war between 1009 and 1013 led to fragmentation of the emirate, with numerous ‘taifas’, independent Muslim city-states, now vying for power. The taifas were unable to protect themselves against the Christian kingdoms to the north, known to the Muslims as the ‘Galician nations’, who were raiding Muslim territory and demanding tribute. These nascent polities had now coalesced into the kingdoms of Navarre, Léon, Portugal, Castile, Aragon and the County of Barcelona and they took advantage of the disarray of their southern neighbours, pushing southwards into Muslim territory. In many cases they were actually invited to assist rulers of taifas in their conflicts with each other, leading to the overall loss of Muslim territory. In 1031 the city of Cordova used Christian mercenaries in the conflict between the caliphate and Berber warriors who had arrived from North Africa. As the Christians began to consolidate their power and extend their territory, Muslims were displaced and marginalized. Christians fighting on behalf of the taifas demanded huge sums of money and supplies, all of which had to be raised through taxes, leading to lack of investment and economic decline, and expediting the taifas’ collapse.
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