A partisan warfare of this kind had long existed between Granada and its most formidable antagonists, the kingdoms of Castile and Leon. It was one which called out the keen yet generous rivalry of Christian and Moslem cavaliers, and gave rise to individual acts of chivalrous gallantry and daring prowess; but it was one which was gradually exhausting the resources and sapping the strength of Granada. One of the latest of its kings, therefore, Aben Ismael by name, disheartened by a foray which had laid waste the Vega, and conscious that the balance of warfare was against his kingdom, made a truce in 1457 with Henry IV., king of Castile and Leon, stipulating to pay him an annual tribute of twelve thousand doblas or pistoles of gold, and to liberate annually six hundred Christian captives, or in default of captives to give an equal number of Moors as hostages,--all to be delivered at the city of Cordova.* * Garibay, Compend., 1.17, c. 3. The truce, however, was of a partial nature, with singular reservations. It did not include the Moorish frontier toward Jaen, which was to remain open for the warlike enterprises of either nation; neither did it prohibit sudden attacks upon towns and castles, provided they were mere forays, conducted furtively, without sound of trumpet or display of banners or pitching of camps or regular investment, and that they did not last above three days.* * Zurita, Anales de Aragon, 1. 20, c. 42; Mariana, Hist. de Espana 1. 25, c. 1; Bleda, Coron. de los Moros, l. 5, c. 3. Aben Ismael was faithful in observing the conditions of the truce, but they were regarded with impatience by his eldest son, Muley Abul Hassan, a prince of a fiery and belligerent spirit, and fond of casing himself in armor and mounting his war-horse. He had been present at Cordova at one of the payments of tribute, and had witnessed the scoffs and taunts of the Christians, and his blood boiled whenever he recalled the humiliating scene. When he came to the throne in 1465, on the death of his father, he ceased the payment of the tribute altogether, and it was sufficient to put him into a tempest of rage only to mention it. “He was a fierce and warlike infidel,” says the pious Fray Antonio Agapida; “his bitterness against the holy Christian faith had been signalized in battle during the lifetime of his father, and the same diabolical spirit of hostility was apparent in his ceasing to pay this most righteous tribute.” CHAPTER II. OF THE EMBASSY OF DON JUAN DE VERA TO DEMAND ARREARS OF TRIBUTE FROM THE MOORISH MONARCH.