In 976, around the same time that Fatimids were building Cairo, the last powerful descendant of Abd al-Rahman died in Cordoba. He left a 12 year old son, Hisham II, with Hisham’s mother as regent.
As so often happened, a child king proved to be a calamity for the nation. Al-Manzur, a powerful vizier, controlled the queen regent’s decisions and isolated the boy in a palace prison. Al-Manzur repeatedly went to war against the Christian kings of Castile and Leon. By 1000, he was ruler over the largest territory of Spain that any Emir or Caliph had ruled yet.
The Fatimid/Ismaili controversies stayed out of Andalusia for the most part. There was no visible sign of trouble in 1000.
Yet at the same time, the vizier al-Manzur was not building a state that could last after his death. After the boy Caliph died, Manzur married the daughter of King Sancho of Navarre as if he were the Caliph himself. He even named his own son Abd al-Rahman, as if they were the real line of Umayyad princes. But he neglected and even ruined some of the traditional Cordoban institutions, such as the library. And in order to win more northern territory, he imported more Berbers as mercenaries.
The Caliphs never seemed to learn the lesson about dangerous mercenaries—or else they really had no other choices. Unlike the Franks, they did not have a feudal tradition with deep loyalty and kinship ties running down through ranks. Frankish kings could count on loyal troops as long as they maintained their traditional duties within feudalism.
Some Muslim lands, including al-Andalus, didn’t seem to have this social structure. Probably this was due to their being elite immigrants who were not related to each other, let alone to the farming population. They ruled at the top, collecting tribute. Extended families might build up power and loyalty within a city, but it didn’t extend to the next city. It was pretty easy for loyalties to be changed, too. What’s based on money can be bought.
After al-Manzur’s death, neither of his sons was able to hold onto power. They were too dependent on North African mercenaries. After 1009, Andalusia was in chronic civil war.
Cordoba had been the central power since Abd Al-Rahman made it his capital in the late 700s. But in 1012, it was ransacked by rebellious Berbers. There must have been so much gold and silver loot in the city to tempt nomadic fighters. The city never recovered in medieval times, and was never again the capital. Scholars fled, perhaps taking with them what books they could carry.
By 1030, Andalusia had no central power. Each city pulled together their local defenses against outside invasion. The strongest leader became a local king. In Arabic, these little city-states were called Taifas. There were at least 30 of them at the start, all fighting and pushing against each other.
More powerful taifas tried to recreate central power. Seville may have had the greatest success, forcing neighboring towns into its tribute/tax structure. Gradually, there were fewer separate taifas, and the map started showing larger mini-kingdoms. But their boundaries were extremely volatile.
Andalusia was ripe for the Reconquista to begin. The Christian kingdoms in the north had sometimes been forced to pay tribute to Cordoba. Now the power balance was reversed. Castile, Leon, and Navarre began to take back town after town. Some taifa rulers paid them tribute in order to stay in power.
Disarray and civil war are always invitations for invasion. But it took about 50 years for a real invasion to happen, so for now, we’ll leave the taifas struggling along like a jigsaw puzzle, with Castile and Leon always growing, pushing southward. Andalusia was no longer part of the regional power balance, threatening either the Fatimids or the Abbasids.