Matthias (24 February 1557 – 20 March 1619) Holy Roman Emperor, King of Germany Reign 13 June 1612 – 20 March 1619
The Bohemians increasingly looked to Bethlen Gábor to save them. The Transylvanian prince had his eyes set on the Hungarian crown, always a more realistic prospect than the Bohemian one. He wrote to the Bohemians on 18 August 1619, announcing he would soon join them in Moravia. This was a ploy to win their support, which would improve his position in negotiations with the Hungarians who were meeting in Pressburg. A wave of re-conversions among the leading Magyar nobles of the western and north-western counties since 1608 had given the Catholics a majority in the diet again. However, neither they nor the Protestants wanted to be drawn into the Bohemian conflict. Bethlen posed as mediator, winning backing from disaffected Upper Hungarian Protestant magnates, like György Rákóczi and Counts Szaniszló and Imre Thurzó. His envoy persuaded the Ottoman grand vizier, Mehmed Pasha, to sanction war against the Habsburgs and promise Turkish infantry as auxiliaries.
Bethlen’s intervention betrayed the problems that would bedevil all Transylvanian involvement in the war. He was convinced Frederick and the Bohemians were rich and would provide the subsidies he needed to keep his largely irregular cavalry army in the field and pay for the infantry and artillery required to take the Habsburg fortresses. For their part, Frederick and his advisers saw what they wanted: a man who claimed to have read the Bible 26 times had to be a crusader of the righteous against Habsburg Catholic tyranny. Bethlen had already demanded 400,000 talers and all of Inner Austria in June, but decided to start operations before Frederick agreed, since he needed a tangible success to convince the Bohemians and the sultan to back him. He left Cluj (Klausenburg) on 26 August with 35,000 men, while Rákóczi entered Kassa unopposed with 5,000 Upper Hungarians a week later. György Széchy and other Upper Hungarian supporters threatened Pressburg to disrupt the efforts of the loyalist Hungarian palatine, Sigismund Forgách, to organize resistance. The Upper Hungarian mining towns declared for Bethlen, but he delayed his own advance to convene a special assembly of supporters at Kassa who declared him ‘Protector of Hungary’ on 21 September, effectively deposing Forgách. Ferenc Rhédey was sent with over 12,000 horsemen across the Little Carpathians into Moravia, while Bethlen resumed his advance with the rest of his army towards Pressburg, destroying a Habsburg detachment sent to save it.
The situation looked dire for the Habsburgs. Garrisons along the Military Frontier declared for Bethlen, leaving only Komorn, Raab and Neutra loyal. Forgách could muster only 2,500 men in the field, while a mere 2,650 under Archduke Leopold held Vienna with a further 560 in Krems and the other Danube towns. Bucquoy and the main army of 17,770 was away around Tabor and Pisek in south-west Bohemia, with Dampierre and 8,600 along the Moravian frontier. The timing was significant. Ferdinand was still on his way back from his coronation in Frankfurt, while the Bohemians had just declared their Confederation and elected Frederick. Bucquoy was obliged to abandon his advance against Prague, leave 5,000 men to hold his current positions and race with the rest to save Vienna.
Panic again gripped the Lower Austrian population as Bethlen’s light cavalry crossed the Danube at Pressburg and swarmed across the area to the south during late October. Refugees crowded into the city, while the rich fled over the Alps. Bucquoy had joined Dampierre, but decided not to risk the emperor’s only army as it was outnumbered three to two by Hohenlohe, Thurn and Rhédey approaching from Moravia. He retreated across the Danube at Vienna, burning the bridge on 25 October. Though they controlled the entire north bank, the Confederates could not reach the city on the other side, and were obliged to march east to cross downstream at Pressburg. Bethlen used the lull to consolidate his position in Hungary. Having captured Forgách at Pressburg, he forced him to convene a diet on 18 November to start the process of deposing Ferdinand as king. The Confederates finally crossed the river on 21 November, and moved west again on the south side, defeating Bucquoy’s attempt to delay them at Bruck five days later. The Lower Austrian Protestants moved 3,000 men east towards Krems, cutting the Habsburg forces off from the other side.
For a third time within a year, the enemy was at the gates of Ferdinand’s capital. Undaunted, the emperor dodged snow, refugees and Transylvanian marauders to re-enter the city. Leopold had made careful preparations since the last attack, stockpiling enough food to feed the 20,000 soldiers and 75,000 civilians who were now inside the city. The besiegers again appeared without heavy artillery and Bucquoy had torched the surrounding countryside so that it could not now sustain the 42,000 troops ringing Vienna. Heavy rain worsened their plight, especially among the Bohemians who had gone months without pay. The promised Turkish auxiliaries had yet to appear. The mutual disillusionment between Bethlen and his allies added to tensions in the Confederate camp where disease halved their effective strength. The final straw was news on 27 November that Transylvania had been attacked. The siege was abandoned a week later, with all the contingents hurrying home except the Bohemians, who remained in Lower Austria