It will be at once seen that those among the Spanish powers which were destined to play the greatest part in later history were not among the first to take the form of separate kingdoms. ♦Slow growth of the greater kingdoms.♦ At this stage even Castile has hardly taken the form of a distinct state. Aragon is only beginning; _Portugal_ has not even begun. ♦History of Castile and Aragon.♦ Of these three, Castile was fated to play the same part that was played by Wessex in England and by France in Gaul, to become the leading power of the peninsula. Aragon, when her growth had brought her to the Mediterranean, was to fill for a long time a greater place in general European politics than any other Spanish power. The union of Castile and Aragon was to form that great Spanish monarchy which became the terror of Europe. ♦Portugal.♦ Meanwhile Portugal, lying on the Ocean, had first of all to extend her borders at the cost of the common enemy, and afterwards to become a beginner of European enterprise in distant lands, a path in which Castile and other powers did but follow in her steps. * * * * * ♦Break-up of the Spanish Caliphate.♦ Meanwhile the advance of the Christians was helped by the division of the Saracenic power. The Caliphates of the East and of the West fell to pieces, exactly as the Christian Empires did. The undivided Mahometan dominion in Spain was at the height of its power in the tenth century. Yet even then, amid many fluctuations, the Christian frontier was on the whole advancing in the north-west. In the north-east Christian progress was slower. ♦1028.♦ But, early in the eleventh century, the Caliphate of Cordova broke in pieces, and out of its fragments arose a crowd of small Mahometan kingdoms at Cordova, Seville, Lisbon, Zaragoza, Toledo, Valencia, and elsewhere. It was now only by renewed invasions from Africa that the Mahometan power in Spain was kept up. But, as the Christian states are now fully formed, such mention of these African dynasties as concerns geography will come more fittingly at a later stage. § 4. _Origin of the Slavonic States._ ♦Slavonic and Turanian invasions.♦