Free Heart of Europe: A History of the Roman Empire by Peter H. Wilson

restricted by the proviso that it should not harm the Empire or emperor. Failure to observe this gave Joseph Ian excuse to sequestrate Bavaria, Cologne and Mantua during the War of the Spanish Succession. 74
    Except for financial support in 1544, the Empire refrained from backing Charles V’s wars against France, compelling him to use his own forces and those he secured by appealing to individual princes. The large numbers of German mercenaries serving him in Italy and the Low Countries were paid for by his own revenues and borrowing. Formal collective action remained limited to policing the western frontiers, especially after 1562, to insulate Germany from the civil wars raging in France and the Netherlands. Measures agreed at Reichstags between 1555 and 1570 failed to prevent either side from recruiting German and Italian troops, but otherwise successfully prevented these conflicts spreading into the Empire, except for Spanish and Dutch incursions in north-west Germany after 1585.
    Like taxation, the main military effort was directed eastwards as Turkish Aid, reflecting the common expectation that the Empire should remain at peace with Christians whilst fulfilling its duty to repel the Ottomans. Substantial contingents were despatched five times from 1532, culminating in a sustained effort during the Long Turkish War, ending in 1606. 75 These were field forces raised for specific campaigns, augmenting troops from the Habsburg lands and much smaller numbers of volunteers from across Europe. Rudolf II opened the Long Turkish War in 1593 with a field army of around 12,000 men from his own lands and 8,000–10,000 from the Empire. 76 The only permanent force comprised 20,000 garrison troops guarding the Hungarian frontier after the 1520s, as well as a gunboat flotilla on the Danube. 77
    Military organization at the territorial level conformed to the imperial structure. Princes and imperial cities maintained small guard units, primarily for status and public order. These provided a professional cadre for contingents sent against the Turks. Peasants were enrolled in territorial militias legitimized by reference to imperial legislation requiring princes to maintain public order and assist the Empire. The militias underwent periodic reorganizations, especially from the 1570s when more systematic drilling was introduced, but they remained comparatively ineffective. Major operations always required professionals, hence the significance of the Empire’s fiscal system to pay them. The Schmalkaldic League and other alliances formed during the sixteenthand early seventeenth centuries all borrowed directly from the Empire’s quota system in their own mobilization structures.
    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. 78 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