John Of Tapoli.--The Instability Of Compacts.--The Sultans's Demands.--A Reign Of War.--Powers And Duties Of The Monarchs Of Bohemia.--The Diet.--The King's Desire To Crush Protestantism.--The Entrance To Prague.--Terror Of The Inhabitants.--The King's Conditions.--The Bloody Diet.--Disciplinary Measures.--The Establishment Of The Order Of Jesuits.--abdication Of Charles V. In Favor Of Ferdinand.--Power Of The Pope.--Paul IV.--A Quiet But Powerful Blow.--The Progress Of The Reformers.--Attempts To Reconcile The Protestants--The Unsuccessful Assembly. During all the wars with the Turks, a Transylvanian count, John of Tapoli, was disputing Ferdinand's right to the throne of Hungary and claiming it for himself. He even entered into negotiations with the Turks, and cooeperated with Solyman in his invasion of Hungary, having the promise of the sultan that he should be appointed king of the realm as soon as it was brought in subjection to Turkey. The Turks had now possession of Hungary, and the sultan invested John of Tapoli with the sovereignty of the kingdom, in the presence of a brilliant assemblage of the officers of his army and of the Hungarian nobles. The last discomfiture and retreat of Solyman encouraged Ferdinand to redoubled exertions to reconquer Hungary from the combined forces of the Turks and his Transylvanian rival. Several years passed away in desultory, indecisive warfare, while John held his throne as tributary king to the sultan. At last Ferdinand, finding that he could not resist their united strength, and John becoming annoyed by the exactions of his Turkish master, they agreed to a compromise, by which John, who was aged, childless and infirm, was to remain king of all that part of Hungary which he held until he died; and the whole kingdom was then to revert to Ferdinand and his heirs--But it was agreed that should John marry and have a son, that son should be viceroy, or, as the title then was, _univode_, of his father's hereditary domain of _Transylvania_, having no control over any portion of Hungary proper.