The Habsburgs tried to fight the Thirty Years War using these structures by claiming that the Bohemian Revolt was a breach of the public peace, while presenting Swedish intervention as a foreign invasion. Throughout, they legitimated their operations by issuing mandates summoning their opponents to lay down their arms and negotiate. Those who failed to respond were branded outlaws to be targeted with punitive action. Habsburg supporters like Bavaria conformed to this approach, since it legitimated their own seizure of lands and titles from the emperor’s enemies. Initially, all belligerents tried to fund war from regular taxes, supplemented by foreign subsidies, forced loans and coinage debasement, the latter causing rampant inflation between 1621 and 1623. Most of the emperor’s early opponents were relatively minor princes who lacked either large territories or reliable foreign backers, and were forced to subsist by extorting money and supplies from the areas where their armies were operating. General Albrecht von Wallenstein’s `contribution system’, adopted by the emperor’s forces after 1625, attempted to regularize this and extended it on an unprecedented scale. Wallenstein hoped to win the war by awe rather than shock, assembling such overwhelming numbers that further fighting would become unnecessary. Drawing on imperial legislation since 1570, Wallenstein issued ordinances regulating what his troops could demand from local communities, thus entirely bypassing regular tax systems. Subsidies and taxes from the Habsburg lands were now reserved to buy military hardware and other items that could not be sourced locally, as well as servicing the loans on which the entire system increasingly depended.
Wallenstein’s system suffered from several major flaws, not least the excessively high pay rates he allowed his senior officers and the rudimentary checks on graft and corruption. The numerous abuses feature prominently in contemporary criticism and subsequent historical discussion, but it was their political implications that made his methods so controversial. Wallenstein’s army tapped the Empire’s resources directly without reference to the Reichstag or the Kreis Assemblies. He gave the emperor an army funded by the Empire, but under Habsburg control and used to wage what was really a highly contentious civil war. Whilst contributions sustained the ordinary soldiers, their officers
The overwhelming desire for peace after 1648 led to the disbandment of virtually all forces in the Empire. Only the Habsburgs retained a small permanent army, which they redeployed in Hungary. However, the wider international situation compelled further discussion of defence. The emperor’s preferred solution was to return to the late sixteenth-century practice of extended Reichstag grants subsidizing the cost of the Habsburgs’ own army. This was politically unacceptable after the experience with Wallenstein. The electorates and several medium-sized principalities established their own permanent forces during the later 1650s and 1660s. The earlier militias were sometimes revived and adapted as a limited form of conscription providing cheap recruits to augment the professionals. The outbreak of almost permanent warfare on the Empire’s western frontier after 1672 saw these forces expand considerably, creating the first true `standing armies’ alongside that of the emperor.
This forged a new divide in the Empire between the `armed Estates’ (Armierten Stände) and their unarmed neighbours. Leopold I relied heavily on the armed Estates who could supply troops fairly quickly during both the Turkish War of 1662-4 and especially in the Dutch War of 1672-9 to defend the Rhine against French attacks. Collective defence became a modified version of Wallenstein’s system as Leopold assigned unarmed territories and cities to provide funds and supplies to support the troops of the armed Estates. Unarmed territories now risked slipping into mediate status under powerful territories like Brandenburg, Saxony, Hanover and the heavily armed bishopric of Münster, all of which tried to formalize their predominance by establishing protectorates. By 1679 it was obvious that the armed Estates intended to deprive unarmed ones of the right to participate in the Reichstag and Kreis Assemblies on the grounds they were no longer meeting their obligations to the Empire directly. This threatened to federalize the Empire through the medialization of smaller territories, shortening the status hierarchy to a collection of large and medium-sized militarized principalities.
Leopold realized this would undermine his ability to manage the Empire and he sided with the lesser imperial Estates at the Reichstag to force through a compromise defence reform in 1681-2, establishing a system of collective security lasting until 1806. The matricular quotas were revised more clearly on a regional basis, retaining the 1521 register for cash contributions, but assigning new manpower contingents to give a basic rate (Simplum) totalling 12,000 cavalry and 28,000 infantry. As before, these could be mobilized as a fraction or multiple of the basic quota. The reform succeeded, because it stabilized the status hierarchy without preventing any further change. The right as well as the duty of all Estates to contribute was confirmed. The role of the Kreise expanded to organize contingents from the smaller territories who could combine their soldiers into regiments of broadly uniform size. The smaller territories could still opt to pay cash in lieu, but the money was now to go through the Reichspfennigmeister (later the Imperial Operations Fund) to prevent them being bullied into unequal local arrangements by more powerful neighbours. All imperial Estates were free to maintain additional troops above what they should provide for the Empire, especially as such obligations were on a sliding scale with no theoretical upper limit. However, this did not amount to the `law of the gun’ (Canonen-Recht) as some critics maintained, because in 1671 Leopold prevented the armed princes from securing the Reichstag’s sanction for unlimited war taxes. Consequently, the legal position remained the one agreed in 1654 that subjects were only obliged to pay for `necessary fortresses and garrisons’, thus still allowing some scope for territorial Estates to decide what these amounted to, as well as for the emperor to intervene when they could not agree. The armed Estates were also still free to provide additional auxiliaries through private arrangements with the emperor that might advance their dynastic goals. Finally, collective defence remained tied to the established constitutional framework governing decisions for war and peace, thus anchored on the ideal of a defensive war, since only this was likely to secure the necessary approval through the Reichstag.
The collective structure was capable of substantial, sustained effort. Although the actual Kreis contingents (Kreistruppen) were always lower than the totals agreed by the Reichstag, it should be remembered that the Habsburgs always subsumed their own contribution within their own army, thus accounting for another 30 per cent above the numbers supplied by the smaller territories. Many of the auxiliaries also included men serving in lieu of Kreis contingents, because many princes wanted to keep all their soldiers together in a single force to increase their weight within the grand coalitions against France. For example, such forces accounted for 28 per cent of the auxiliaries provided during the War of the Spanish Succession.
The continuous warfare saw the total number of soldiers maintained by the emperor and imperial Estates rise from 192,000 in 1683 to peak at 343,300 in 1710. The most significant and surprising aspect of this rapid militarization was the disproportionate growth amongst the smaller territories, whose total strength grew by 95 per cent to reach 170,000 men, compared to a 75 per cent increase in the Prussian army to 43,500, and a 62 per cent rise in Habsburg strength to 129,000. Thus, imperial defence imposed a heavy burden on the Empire’s weakest elements, but this simultaneously ensured their political survival. The Westphalian and Upper Saxon minor territories used the Kreis structure to organize their own contingents, enabling them after 1702 to break free from onerous arrangements imposed by Prussia, Saxony and the Palatinate, which had previously provided troops to the imperial army on their behalf. In contrast to the almost universal disbandment in 1648, the Westphalian, Upper Rhenish, Electoral Rhenish, Swabian, Franconian and Bavarian Kreise agreed in 1714 to remain armed in peacetime by maintaining contingents at one and a half times the basic quota. Perhaps more surprising still is that militarization remained contained by a highly legalistic political culture (unlike, say, China in the 1920s where warlords created their own provincial armies with little regard to the republic’s formal order). Despite their lands being the most heavily armed part of Europe, the German princes continued to submit their disputes to judicial arbitration through the imperial courts, rather than make war on their neighbours.
The collective system mobilized 34,200 Kreis troops for the 1735 campaign during the War of the Polish Succession (1733-5) against France, while at least 112,000 recruits and auxiliaries were supplied to the Habsburg army across 1733-9.86 The disappointing outcome of this campaign and the parallel Turkish War (1736-9) combined with political disillusionment with the Habsburgs and the disaster of Wittelsbach imperial rule between 1742 and 1745 to weaken collective defence. Most territories reduced their peacetime forces and several withdrew from military cooperation at Kreis level. This trend was compounded by the underlying shift in the Empire’s internal military balance as the combined strength of the Austrian and Prussian armies expanded from 185,000 men in 1740 to 692,700 fifty years later, compared to the combined total of all other forces that dropped by around 9,000 men to 106,000 by 1790.