The Thirty Years’ War had reached its final phase, and broad swathes of the Empire devastated and depopulated. A military victory was becoming ever more unlikely for all the parties involved. The House of Habsburg was facing the ruins of its exaggerated claims to dominion.
In 1637 Ferdinand assumed rule over a realm that had been weakened by nearly twenty years of warfare. With the entry into the war of Sweden (1630) and France (1635) the Habsburg Monarchy was now confronted with powerful adversaries.
The initial successes of the early phase of the war were now followed by a series of damaging defeats, for example the Battle of Jankau in 1645, in which the imperial troops were annihilated. The army lacked strong leadership. The Viennese court was anxious to avoid letting any dominant personalities rise to high rank, fearing a recurrence of an over-powerful supreme commander like Wallenstein.
Moreover the emperor was in financial difficulty because of spiralling military expenditure: in the warfare of the time loyalty could only be purchased with money. Any stoppages in pay would have risked the trustworthiness of the officer corps since military commanders were entrepreneurs who financed their armies of mercenaries in advance and settled up with the Court Chamber (Hofkammer) afterwards.
The emperor gradually became dependent on loans and financial help from the Austrian and Bohemian higher nobility, who in this way secured a monopoly on lucrative and influential positions at court and in the state administration. As a result of the massive shift in assets following the suppression of the revolt by the Bohemian Estates and the galloping inflation that had ensued from the debasing of the currency in the 1620s, an oligarchic group of nobles had formed which dominated the financial world of the Habsburg Monarchy. Ferdinand fought an unavailing battle to reform the financial administration and combat corruption.
The lowest point was reached in 1645, when the Swedish army took control of the Bohemian lands and advanced to the Danube, almost to the gates of Vienna. Peasant unrest threatened, and the Protestants who had been driven underground also reappeared under Swedish protection. This showed how superficial the forced re-Catholicization of large sections of the population had been. Now the end had come for these imperial fantasies of omnipotence, the emperor’s unrealistic dreams of hegemony in the Empire and Europe. It was now imperative to ensure that Habsburg dominion could at least be preserved in the patrimonial dominions.