Al Mamun, the host and protector of Alfonso VI., had died in 1075, leaving, his grandson, Cadir, to succeed him as sovereign of Toledo. Abdulaziz, the viceroy of the subject city of Valencia, took advantage of the weakness of the young prince to declare himself independent, and placing himself under the protection of the Christians, undertook to pay a large subsidy to Alfonso VI. in return for his recognition and support. The subsidy was punctually paid, and, in spite of a present of no less than a hundred thousand pieces of gold handed over by Moctadir of Saragossa to Alfonso as the price of Valencia, Abdulaziz retained his hold of the city until his death in 1085. On this, numerous pretenders to the government immediately arose, including Moctadir of Saragossa, a purchaser for value, and the two sons of Abdulaziz; while Alfonso took advantage of the confusion that ensued to persuade Cadir to surrender Toledo, much coveted by the Christian king, and to accept, or, more exactly, to retain, for himself the sovereignty of Valencia, under the humiliating protection of Castile. Alfonso cared nothing that Toledo was the inheritance of his youthful ally, the home of his old protector, when he himself was a hunted refugee. He cared nothing that the Valencians were hostile to Cadir, and that powerful neighbors were prepared to dispute his possession. He cared nothing that Moctadir, who had actually purchased the city from Alfonso himself, was on the way to make good his claim. A treaty was forced upon Cadir by which Toledo was surrendered to Alfonso VI. (1085), and the Christian king was bound to place and maintain the unhappy prince in possession of his own subordinate city of Valencia.