Charles V. was apparently in a very strong position. Not since the days of Charlemagne had any ruler claimed jurisdiction over so wide a territory as his, comprising, as it did, Germany and Austria, the kingdom of the two Sicilies, Spain, and the Netherlands. But in reality the very extent of his dominions made him much less powerful than he might have been as the sovereign of a smaller but more compact region. It served to awaken the suspicions of his subjects, who feared that he might abolish their distinctive national constitutions and weld his scattered territories into one great empire, and to excite the jealousy of the other rulers of Europe, who imagined that he might declare himself dictator of the western world. The German princes, having resisted successfully all the efforts made by his grandfather, Maximilian I., to convert the loose confederation of the German States into a united and centralised nation, were on their guard lest his successor should attempt a similar policy with the aid of Spanish troops and Spanish gold; the Spaniards resented the absence of the king from Spain, where many of the lower classes were in a state bordering on rebellion; Francis I. of France, trembling for the very existence of his country, was willing to do all things, even to agree to an alliance with the sons of Mohammed, if he could only lessen the influence of his powerful rival. The Turks under Soliman I. were determined to realise the dreams of their race by extending their territories from the Bosphorus to the Atlantic; while even the Pope had good reason to suspect that Charles V., unmindful of the example of his great namesake, might seek to become the master rather than the protector of the Church.[19] On account of the troubles in Spain it was only late in the year 1520 that Charles V. could come to Germany to meet the electors, and to take over formally the administration of the Empire (23 Oct.). Less than two weeks had elapsed when the papal representative, Aleandro, himself a distinguished Humanist, sought an interview with the new ruler, and besought him to enforce the papal Bull against Luther with the full weight of his imperial authority. But the wavering attitude of many of the princes and the determined opposition of Frederick of Saxony made the Emperor hesitate to condemn Luther without giving him an opportunity for explanation and defence. The Diet was soon to open at Worms, and Charles V. issued an invitation to Luther to attend, guaranteeing at the same time his personal safety on the way to and from Worms and during his sojourn in the city.