1451 recognized his title, which was also sanctioned by the emperor Frederick III., guardian of the young king. Podebrad was none the less opposed, almost from the first, by the Romanists, who even concluded an alliance against him with their extreme opponents, Kolda of Zampach and the other remaining Taborites. In October 1453 Ladislas arrived in Bohemia and was crowned king at Prague; but he died somewhat suddenly on the 23rd of November 1457. George of Podebrad has from the first frequently been accused of having poisoned him, but historical research has proved that this accusation is entirely unfounded. The Bohemian throne was now again vacant, for, when electing Ladislas the estates had reaffirmed the elective character of the monarchy. Though there were several foreign candidates, the estates unanimously elected George of Podebrad, who had now for some time administered the country. Though the Romanist lords, whom Podebrad had for a time won over, also voted for him, the election was considered a great victory of the national party and was welcomed with enthusiasm by the citizens of Prague. During the earlier and more prosperous part of his reign the policy of King George was founded on a firm alliance with Matthias Corvinus, king of Hungary, through whose influence he was crowned by the Romanist bishop of Waitzen. The reign of King George, whose principal supporters were the men of the smaller nobility and of the towns, was at first very prosperous. After a certain time, however, some of the Romanist nobles became hostile to the king, and, partly through their influence, he became involved in a protracted struggle with the papal see. It was in consequence of this struggle that some of George's far-reaching plans--he endeavoured for a time to obtain the supremacy over Germany--failed. After the negotiations with Rome had proved unsuccessful George assembled the estates at Prague in 1452 and declared that he would to his death remain true to the communion in both kinds, and that he was ready to risk his life and his crown in the defence of his faith. The Romanist party in Bohemia became yet more embittered against the king, and at a meeting at Zelena Hora (Grunberg) in 1465 many nobles of the Roman religion joined in a confederacy against him. In the following year Pope Paul II. granted his moral support to the confederates by pronouncing sentence of excommunication against George of Podebrad and by releasing all Bohemians from their oath of allegiance to him. It was also through papal influence that King Matthias of Hungary, deserting his former ally, supported the lords of the league of Zelena Hora. Desultory warfare broke out between the two parties, in which George was at first successful; but fortune changed when the king of Hungary invaded Moravia and obtained possession of Brunn, the capital of the country. At a meeting of the Catholic nobles of Bohemia and Moravia at Olmutz in Moravia, Matthias was proclaimed king of Bohemia