This, then, was their mission. And it is interesting to see how faithfully they fulfilled it; and during the long period of the Middle Ages, when other nations were occupied with base feudal quarrels or border warfare, it is curious to observe the Spaniard intent on the one great object of reclaiming his country from the possession of the infidel. It was a work of time; and his progress, at first almost imperceptible, was to be measured by centuries. By the end of the ninth century it had reached as far as the Ebro and the Douro. By the middle of the eleventh, the victorious banner of the Cid had penetrated to the Tagus. The fortunes of Christian Spain trembled in the balance on the great day of Navas de Tolosa, which gave a permanent ascendancy to the Castilian arms; and by the middle of the thirteenth century the campaigns of James the First of Aragon, and of St. Ferdinand of Castile, stripping the Moslems of the other southern provinces, had reduced them to the petty kingdom of Granada. Yet on this narrow spot they still continued to maintain a national existence, and to bid defiance for more than two centuries longer to all the efforts of the Christians. The final triumph of the latter was reserved for the glorious reign of Ferdinand and Isabella. It was on the second of January, 1492, that, after a war which rivalled that of Troy in its duration, and surpassed it in the romantic character of its incidents, the august pair made their solemn entry into Granada; while the large silver cross which had served as their banner through the war, sparkling in the sunbeams on the red towers of the Alhambra, announced to the Christian world that the last rood of territory in the Peninsula had passed away for ever from the Moslem. [Sidenote: EFFORTS TO CONVERT THEM.]