after the failure of the Conciliar movement at Basel implied, with all its renunciation of high ideals, the establishment of a workable system that kept the peace until the outbreak of the Reformation. The Vienna Concordat of 1448 put an end to that tendency towards the 'nationalisation of the German Church which had been promoted so powerfully by the attitude of the prelates of the German nation at the Council of Constance, and which had been maintained so long when, under the guidance of Emperor and Electors, the Germans had upheld their neutrality between both the disorderly fathers at Basel and the grasping papal Curia at Rome. In the long run this nationalising tendency must have extended itself from ecclesiastical to political matters. Even in the decline of the Middle Ages the union within the Church might well have prepared the way to the union of the State. In accepting a modus vivendi which gave the Pope greater opportunities than now remained to the Emperor of exercising jurisdiction and levying taxation in Germany, Frederick proved himself a better friend to immediate peace than to the development of a national German State.
Three signal successes gilded the end of Frederick's long reign. The power of the House of Burgundy threatened to withdraw the richest and most industrial parts of the Empire from the central authority. But the sluggish Emperor and the inert Empire were at last roused to alarm, when Charles the Bold made the attack on their territory that began with the siege of Neuss. It was an omen of real possibilities for the future when a great imperial army gathered together to relieve the burghers of the Rhenish town. The "New League" of the Alsatian cities which was formed to ward off Charles' southern aggressions was a step in the same direction. And even the "Old League" of the Swiss Highlanders, which finally destroyed the Burgundian power, was not as yet avowedly anti-German in its policy. But, as in Church affairs, Frederick stepped in between the nation and its goal. At the moment of the threatened ruin of his ancient enemy's plans, he cleverly negotiated the marriage of his son Maximilian with Mary, the heiress of Charles the Bold. Soon after the last Duke of Burgundy had fallen at Nancy, Maximilian obtained with the hand of his daughter the many rich provinces of the Netherlands and the Free County of Burgundy (1477). It was not however for the sake of Germany or the Empire that Frederick sought a new sphere of influence for his son. The Burgundian inheritance remained as particularistic and as anti-German under the Habsburgs as it had ever been under Valois rule. But the future fortunes of Austria were established by an acquisition which more than compensated the dynasty for the loss of Hungary and Bohemia.
The other late successes of Frederick were likewise triumphs of Austria rather than victories of the Empire. The Duke of Bavaria-Munich had profited by the internal dissensions of the House of Habsburg and won the goodwill of the aged Archduke Sigismund of Tyrol. It