As the spider, after his glistening habitation has been destroyed by some ruthless footstep, goes patiently to work to rebuild it, so the Moor in Granada, with his imperishable instinct for beauty, was making of his little kingdom the most beautiful spot in Europe. The city of Granada was lovelier than Cordova; its Alhambra more enchanting than had been the palaces in the "City of the Fairest." This citadel, which is fortress and palace in one, still stands like the Acropolis, looking out upon the plain from its lofty elevation. Volumes have been written about its labyrinthine halls and corridors and courts, and the amazing richness of decoration, which still survives--an inexhaustible mine for artists and a shrine for lovers of the beautiful. But Granada cultivated other things besides the art of beauty. Nowhere in Europe was there in the thirteenth and fourteenth centuries such advanced thinking, and a knowledge so akin to our own to-day, as within the borders of that Moorish kingdom. CHAPTER XV. There were other reasons beside the growing peacefulness of the Spaniards why Granada was left to develop in comparative security for two centuries. It was impossible that adjacent ambitious kingdoms, such as Navarre, Castile, Aragon, Leon, and Portugal, with indefinite and disputed boundaries, and, on account of intermarriages between the kingdoms, with indefinite and disputed successions, should ever be at peace. In the perpetual strife and warfare which prevailed on account of royal European alliances, the fate of foreign princes and princesses were often involved, and hence European states stood ready to take a hand. Castile and Aragon had gradually absorbed the smaller states, excepting Portugal on the one side and Navarre on the other. The history of Spain at this time is a history of the struggles of these two states for supremacy. The most eventful as well as the most lurid period of this prolonged civil war was while Pedro the Cruel was king of Castile, 1350-69. This Spanish Nero, when sixteen years old, commenced his reign by the murder of his mother. A catalogue of his crimes is impossible. Enough to say that assassination was his remedy, and means of escape, from every entanglement in which his treacheries involved him. It was the unhappy fate of Blanche de Bourbon, sister of Charles V., King of France, to marry this King of Castile, and when he refused to live with her and had her removed from his palace the Alcazar to a fortress, and finally poisoned her, the French King determined to avenge the insult to his royal house. He allied himself with the King of Aragon to destroy Pedro, with whom the King of Aragon was of course at war.