Castile and Aragon, now being indissolubly united, and internal peace secured, it was time for the sovereigns to prepare for the execution of the great designs that had respectively moved them to effect what they had done. These designs were to some extent divergent from each other. Ferdinand’s main object was to cripple his rival, France, in the direction of Italy, and assume for Aragon the hegemony of the Mediterranean and of the sister Peninsula, of which Sicily already belonged to him and Naples to a member of his house. Castile, on the other hand, had for centuries cultivated usually harmonious relations with France, the frontiers not being conterminous except at one point, the mouth of the Bidasoa; and the ambitions of Castile were traditionally towards the absorption of Portugal, the domination of the coast of North Africa, and the spread of the Christian power generally to the detriment of Islam, its secular enemy. Its own Moorish populations were as yet but imperfectly assimilated, and the existence of the realm of Granada in the Peninsula kept hopes alive in the breasts of the Castilian Moors. The presence of many thousands of potential enemies in the midst of Christian Spain, and the wealth and number of the Jews, who, in a struggle, would probably side with the Moors, undoubtedly influenced greatly in causing the severity of the Inquisition against them and their subsequent expulsion. The first step, therefore, to be taken towards the objects either of Aragon and Castile, was to reduce to impotence any Moorish power in Spain itself that might cause anxiety to the Christian rulers whilst they were busy upon plans abroad, though this step was mainly important to Castile rather than to Aragon.
This was the state of affairs in the beginning of 1481. The Castilians were subdued and prepared to do the bidding of their Queen, but the Catalans and Aragonese, rough and independent, had to be conciliated before they could be depended upon to give their aid to an object apparently for the advantage of Castile. Isabel had summoned a Cortes of her realms to the imperial city of Toledo late in 1480, to take the oath of allegiance to her infant son Juan as heir to the throne: and thence, with a splendid train, she rode to visit for the first time her husband’s kingdoms, to receive their homage as joint sovereign. Ferdinand met his wife at Calatayud in April 1481, and there, before the assembled Cortes of Aragon, the oath of allegiance to the sovereigns and their heir was taken. The Aragonese were rough-tongued and jealous, and even more so the Catalans, dreading the centralising policy of Isabel and their assimilation by Castile; and throughout Ferdinand’s dominions Isabel was forced to hear demands and criticisms to which the more amenable Cortes of Castile had not accustomed her. It was gall and wormwood to her proud spirit that subjects should haggle with monarchs, and in Barcelona she turned to her husband, when the Cortes had refused one of his requests, and said: ‘This realm is not ours, we shall have to come and conquer it.’ But Ferdinand knew his subjects better than she, and gradually made them understand that in all he did he had their interests in view. He was forced, indeed, by circumstances and his wife to allow precedence to Castilian aims, the better to compass those of Aragon.