 Ferdinand reasonably feared that he would not be capable of repelling an Ottoman attack to Spain's shores, especially if the Ottomans had internal help.The regions with the highest concentration of Moriscos were those close to the common naval crossings between Spain and Africa.If the weakness of the Aragonese Naval Empire was combined with the resentment of the higher nobility against the monarchs, the dynastic claims of Portugal on Castile and the two monarch's exterior politic that turned away from Morocco and other African nations in favor of Europe, the fear of a second Muslim invasion, and thus a second Muslim occupation was hardly unfounded.