Alphonso III. succeeded to the regal dignity. Jealous of the rights of sovereignty, and determined to transmit them unimpaired to his successor, his reign was, in consequence, a perpetual contest with the intrigues of the clergy. Inflexibly firm and resolute, he defeated their artful attempts to extend their landed estates; to obtain exemption from taxation; to acquire for their persons and possessions an independence of secular jurisdiction; and to subject the temporal to the spiritual authority by an insidious and gradual encroachment on the rights of the crown. Dionysus, who succeeded Alphonso III., opposed with prudence and firmness the papal intrigues, which had disturbed the peace of the kingdom from its foundation. In order to moderate the selfishness and tyranny of the first and second estates, composed of the clergy and nobility, he erected the cities into a third estate, of equal legislative authority. By elevating the dignity of the commonality, and taking advantage of the commercial resources which the geography of the country afforded, he awakened in the nation a spirit of indomitable enterprise which laid the foundation of its subsequent greatness. This liberal and enlightened policy cost him the friendship of the papal court, but he disarmed its malice by an admirable course of prudence and courtesy. John II. became King of Portugal in 1450. During his administration Ferdinand and Isabella, of Spain, governed by the spirit of Catholic intolerance, instituted a rigorous prosecution against the Jews, by which thousands of them were deprived of their fortunes, and driven into exile. The Jews had arisen in Spain into considerable political influence; they had become farmers of the revenue; and their characteristic avarice had rendered them obnoxious to the people. Instead of rectifying the evil by adequate measures, the crown and people, influenced by the church, were made instrumental in gratifying its hatred against the Hebrew race, by a persecution as unjust as it was impolitic. John II., with more liberal views of government, improved the injudicious measures of Spain, to the advantage of his own kingdom. Discarding the intolerance of his religion, he invited the persecuted Jews to his dominion; and by affording them a peaceful asylum, added largely to the wealth, population, prosperity and importance of the nation.