His two leading enemies were Rupert, Count Palatine of the Rhine, who aimed at the Imperial dignity, and the Archbishop of Mainz, who had secured his see by a promise to support the intrigues of Rupert. These conspirators succeeded in winning to their side Pope Boniface IX. This Pope had indeed been at first friendly to Wenceslaus; but he had been offended by the readiness with which the King of Bohemia had listened to the French proposals for the election of a new Pope in place of the two rival claimants to the Holy See. Under various pretexts, the Duke of Saxony and the Archbishops of Trier and Köln were drawn into the conspiracy; and so, in February, 1400, the Electors met at Frankfort and resolved to choose a new Emperor.
The most plausible grounds for this deposition were mainly of a negative kind. Wenceslaus was charged with failing to procure a peaceful settlement of the affairs of the Church, and with paying no heed to those wars which were disturbing the Empire. Though Wenceslaus might have found ample excuse for these failures, he could not directly deny them; but the other charges were either false or grossly exaggerated. One of them, however, must be quoted, since it has so much bearing on the troubles which were approaching in the Bohemian kingdom. This was a charge that he “had drowned, burnt, and otherwise murdered and tortured reverend prelates and priests.” This accusation shows that the murder of Nepomuc was to be represented, at the pleasure of Wenceslaus’s enemies, either as part of a general massacre of priests, or as the cruel execution of one specially righteous man.
It was, therefore, as the champion of Holy Church against its oppressor, that Rupert was chosen Holy Roman Emperor. In this character he at once marched into Bohemia and won the support of Jodok and the discontented nobles. Again Wenceslaus was forced to make terms with his enemies; and again Sigismund was called in and appointed Viceroy. But Sigismund gained favour with no party. Jodok and his friends resented the power entrusted to him; the citizens of Bohemia complained of the heavy taxes which he laid upon them; and Wenceslaus resisted his proposal that he should counteract the schemes of Rupert by accompanying Sigismund to Rome, and by accepting the Imperial crown from the Pope. Finding his plans thwarted, Sigismund suddenly seized upon his brother, and carried him off as prisoner to Vienna. From this imprisonment Wenceslaus succeeded in escaping in 1403; and, on his return to Prague, he was welcomed as the liberator of Bohemia from Sigismund.