The weakening of the power of the Cordovan caliphate in its northern provinces, as a result of the revolt of the Beni Hassan in 864, was singularly favourable to the development of the small Christian states. The tenth century, however, did not continue to bring uninterrupted good fortune to the Christian states. While discords were beginning to creep in among their own number, the caliphate was restored by Abd ar-Rahman III, and the adroit Al-Mansur under Hisham II. The terrible defeat suffered by the Christians at Simancas in 940, the overthrow of Sancho the Great by the count of Castile who declared himself independent, and the subsequent reinstatement of Sancho by Abd ar-Rahman, reveal the kingdom of Leon as having fallen into a state of demoralisation so deep that even its enemies had power to dispose of the throne. Al-Mansur also weighed upon the Christians with a ruthless hand. In 997 he found himself master of all the lands the Christians had conquered south of the Douro and the Ebro. When he came to be defeated himself, however, at Calatanazar, near the source of the Douro, his chagrin was so great that he allowed himself to die by starvation, and in him perished the mainstay of the caliphate (998).
We have seen at another point in this history that during the eleventh century the Spanish Arabs fell into complete dissolution; the Christian states, on the other hand, grew into closer and closer union by means of frequent intermarriages and increased trade relations. This process of unification and internal adjustment, as well as the necessity of closing all the gaps left open by the sword of Al-Mansur, held in check the holy war for a period of nearly a century. At the end of that time it was resumed with greater brilliancy and success than before.
Not alone by reason of the fortunate alliances he was able to make did Sancho II merit the title of Great; greatness was to be achieved in Spain mainly by warring upon infidels, and many were the engagements during which the Moors were made to feel the might of his sword. Not content to rest here, he carried his victorious arms, in the intervals of preparing the substitution of the Christian dynasty of Aznar for that of Pelayo, into the heart of the Moslem country to the very walls of Cordova.
[1072-1146 A.D.]
At Sancho’s death Spain was divided into four kingdoms. But Alfonso VI reunited Castile and Leon in 1072, and resumed in Spain the holy war which had been made extremely popular in Europe by the preparations for the First Crusade. The news of the Christian reverses in Jerusalem, and also the growing influence of the holy see, had a powerful effect on Spain. It was the desire of Gregory VII to bring under his domination the Spanish Christian states which had hitherto enjoyed complete religious independence, and in case of their failure to yield it was feared that some day he would arm all Christianity against them.
Always characterised by boundless presumption, Gregory VII demanded of Alfonso VI that he pay him tribute, on the pretext that all lands taken from the infidels were by right the property of the church. Alfonso refused. Then Gregory fell back on another point, the adoption by the Spanish Christians of the Roman instead of the Gothic or Muzarabic ritual to which they had been used. Eventually Alfonso adopted the Roman ritual. Henceforth complete communion was held with Rome by the Spanish people which eventually became the most pronouncedly Catholic, if not always the most submissive to the holy see, of all the races of the earth.
Ferdinand I had profited by the divisions existing among the petty Arab sovereigns to wrest from them many of their possessions. He took Viseu, Lamego, Coimbra, and made the king of Toledo pay him tribute. In 1085 Alfonso VI was even more successful, gaining possession of the entire kingdom. Toledo, formerly the capital and metropolis of the Goths, became once more an important centre; and its restoration marks the fourth stage of the progress of the Christians from the Asturias, where they began their onward march, to the heart of the peninsula, where they were to take up a firm position behind the barrier of the Tagus.