The accession of Charles of Spain to the Imperial throne took place in October of the same year as Suleiman’s accession, 1520. Handicapped in every possible way by the German princes, for whose safety and prosperity the emperor assumed the entire responsibility without receiving in return any equivalent whatever,[93] Charles V presented a great contrast to Suleiman, whose slightest word was law throughout his extensive dominions. With the empire, Charles acquired the enmity of Francis I of France, his unsuccessful rival, and hereafter his constant foe. Another rival not outwardly so dangerous, but destined to be a great source of anxiety and weakness to the empire was Ferdinand, the emperor’s brother. Concerning him, Charles’ counsellor, de Chièvres, is reported to have said to Charles,[94] “Do not fear the king of France nor any other prince except your brother”. Ferdinand’s ambition had been early recognized. His grandfather, Ferdinand of Aragon, had attempted to construct an Italian kingdom for him, but failed. Charles, after his election to the Empire, tried to satisfy Ferdinand’s craving for power by conferring on him the old Austrian provinces, and further by marrying him to Anna, heiress of the kingdom of Hungary and Bohemia, whose child‐king, Lewis, was weak physically and not destined for a long reign. This opened to Ferdinand a large sphere of activity in the southeast, and brought him into direct contact with the steadily encroaching Suleiman; a sphere that effectually absorbed his energies and made him but a source of weakness to the Empire. Thus Charles V, in name the imperial ruler of Central Europe, was confronted with four rivals who desired to divide with him the supremacy; Francis I, a relentless foe; his brother Ferdinand, an ambitious claimant: the conquering Suleiman; and the Protestant Revolt. The weakness and disunion of Christendom was the strength of Suleiman, and he was far too shrewd not to trade on it.