could have been over in fewer than thirty months. However, the death of Emperor Matthias emboldened the rebellious Protestant leaders, who had been on the verge of a settlement. The weaknesses of both Ferdinand (now officially on the throne after the death of Emperor Matthias) and of the Bohemians themselves led to the spread of the war to western Germany. Ferdinand was compelled to call on his cousin, King Philip III of Spain, for assistance. The Spanish Crown had interests in maintaining the Holy Roman Empire as a stable ally; a critical trade route, the "Spanish Road", extended from the Mediterranean to Brussels. To this end they invested an enormous sum of treasure in the hiring of free companies and mercenaries. The Bohemians, desperate for allies against the Emperor, applied to be admitted into the Protestant Union, which was led by their original candidate for the Bohemian throne, the Calvinist Frederick V, Elector Palatine. The Bohemians hinted Frederick would become King of Bohemia if he allowed them to join the Union and come under its protection. However, similar offers were made by other members of the Bohemian Estates to the Duke of Savoy, the Elector of Saxony, and the Prince of Transylvania. The Austrians, who seemed to have intercepted every letter leaving Prague, made these duplicities public. This unraveled much of the support for the Bohemians, particularly in the court of Saxony. Even James I of England refused to support Frederick, despite his wife being James' daughter. Overall, England was criticized for its inaction in the Thirty Years' War. In spite of these issues surrounding their support, the rebellion initially favoured the Bohemians. They were joined in the revolt by much of Upper Austria, whose nobility was then chiefly Lutheran and Calvinist. Lower Austria revolted soon after, and in 1619, Count Thurn led an army to the walls of Vienna itself. Defeat of the revolt The Spanish sent an army from Brussels under Ambrogio Spinola to support the Emperor. In addition, the Spanish ambassador to Vienna, Don Íñigo Vélez de Oñate, persuaded Protestant Saxony to intervene against Bohemia in exchange for control over Lusatia, in addition they would invest nearly two million ducats in the supply and payment of both the army and its free company contingents. The Saxons invaded, and the Spanish army in the west prevented the Protestant Union's forces from assisting. Oñate conspired to transfer the electoral