Then, for the space of two hundred and forty years, there was a comparative lull. Under the enlightened rule of the Nasride dynasty the province of Granada enjoyed a prosperity that invited friendly relations even with the Christians. The wealth derived from its mines, industries and agriculture exceeded that of the ancient Caliphate of Cordova. The period represented, in fact, the Golden Age of Moorish civilization in Spain, the flower and symbol of which remains to-day, though shorn of much of its magnificence, in the still exquisite palace of the Alhambra. So skilfully by treaty and otherwise did the rulers of Granada conciliate the Christians that their reign might have been continued indefinitely, but for two causes: internal dissensions and the fixed idea of Ferdinand and Isabella to fulfil their obligations as Catholic Kings. They lived for the purpose of expelling the infidel, and the rivalry between the two great Moorish tribes, the Zegri and the Abencerrages, gave them the opportunity. It had resulted in the throne being occupied by the youthful weakling, Boabdil. He fell into the hands of Ferdinand and Isabella at the battle of Lucena, and consented to remain neutral while they attacked the coast cities of Granada. Finally they appeared before Granada itself and Boabdil, after a frantic but futile effort to oppose them, was forced into a treaty of peace, by which the city was surrendered. Ten years later the last of the Moors had been expelled from Spain or compelled to be baptised.