Both Rudolph and Matthias had committed themselves to the toleration of the Reformed religion. The famous "Majesty-Letter," freshly granted by the Emperor (1609), and the Compromise between the Catholic and Protestant Estates had become the law of the land. Those of the Bohemian confession, a creed commingled of Hussism, Lutheranism, and Calvinism, had obtained toleration. In a country where nine-tenths of the population were Protestants it was permitted to Protestants to build churches and to worship God in them unmolested. But these privileges had been extorted by force, and there was a sullen, dogged determination which might be easily guessed at to revoke them should it ever become possible. The House of Austria, reigning in Spain, Italy, and Germany, was bound by the very law of their being to the Roman religion. Toleration of other worship signified in their eyes both a defeat and a crime. Thus the great conflict, to be afterwards known as the Thirty Years' War, had in reality begun already, and the Netherlands, in spite of the truce, were half unconsciously taking a leading part in it. The odds at that moment in Germany seemed desperately against the House of Austria, so deep and wide was the abyss between throne and subjects which religious difference had created. But the reserved power in Spain, Italy, and Southern Germany was sure enough to make itself felt sooner or later on the Catholic side. Meantime the Estates of Bohemia knew well enough that the Imperial house was bent on destroying the elective principle of the Empire, and on keeping the crown of Bohemia in perpetuity. They had also discovered that Bishop-Archduke Leopold had been selected by Rudolph as chief of the reactionary movement against Protestantism. They could not know at that moment whether his plans were likely to prove fantastic or dangerous.