By the accession of Isabella to the throne of Castile in 1474, and of her husband, Ferdinand the Catholic, to that of Aragon in 1479, not only did these two countries escape from a long period of internal anarchy, but the rivalry hitherto existing between Castile and Aragon was put an end to, and, while the autonomy of the two governments was preserved, the policy which guided them was one. In their determination to increase the power of the crown at home and the prestige of their nation abroad, Isabella and Ferdinand were in singular agreement. The most startling events of their reigns either occurred before the beginning of our period, or have been already mentioned. In 1492, Granada had been conquered from the Moors; and the expulsion of the Jews, the establishment of the Inquisition, even the discovery of Hispaniola by Columbus, had also occurred before the Italian wars. | The Policy of Ferdinand and Isabella. Marriage Alliances. At this time, the policy of Ferdinand and Isabella was mainly devoted to the formation of a great European alliance based upon the tie of marriage, whereby they might at once strengthen themselves against the formidable power of France, and contribute to the further consolidation of the Spanish Peninsula. With this end in view, their eldest daughter, Isabella, was given in marriage to Alonso, the Prince of Portugal, and on his death to his kinsman, Emanuel, who ascended the Portuguese throne in 1495. To this period also belongs the betrothal of Catherine, their youngest daughter, with Arthur, Prince of Wales (1496), an alliance which brought England into intimate relations with Spain for the first time since the days of John of Gaunt. More important was the double marriage treaty with the House of Hapsburg. It was agreed that John, the heir to the Spanish kingdom, should marry Margaret, the daughter of the Emperor Maximilian, and that the Archduke Philip, the son and heir of Maximilian, should marry Joanna, second daughter of the Spanish monarchs. The hopes founded on these marriages by Ferdinand and Isabella were not, however, realised. By the death of their only son John in 1497, and by that of Don Miguel, only son of Isabella of Portugal, in 1500, all hopes of uniting Portugal to Spain were destroyed; and Joanna, the wife of the Hapsburg prince, and mother of Charles V., became heiress of Castile and Aragon. Thus an alliance which had been originally made to protect the balance of power against France, was eventually to destroy that balance in the interest of the House of Hapsburg. | Their internal Policy.