The eighteenth century is the period in which the empire's two principal internal questions — the rise of Brandenburg-Prussia as a peer to the Habsburg monarchy, and the structural decline of the imperial diet and courts as instruments of central authority — became simultaneously decisive. By the end of the century, on the eve of the French Revolution, the empire as a coherent political entity had become substantially decorative: its formal institutions still functioned in routine matters, but the dynastic rivalry between Austria and Prussia (the dualism that would define German politics for the next 150 years) had displaced the imperial frame as the operative arena of central-European politics. The institutional decline was masked, until the 1790s, by the absence of a major external shock that would test the empire's capacity to defend itself. The French Revolution would supply the test, and the empire would fail it.
The Habsburg succession crisis
The major dynastic crisis of the period was the Habsburg succession. The emperor Charles VI (1711–1740) had no male heir; his daughter Maria Theresa, born 1717, was therefore his designated successor under the Pragmatic Sanction of 1713, an internal Habsburg succession arrangement that Charles spent the rest of his life persuading the European powers to recognise. The Pragmatic Sanction was accepted, with varying degrees of sincerity, by most of the European powers in the 1730s. When Charles died in October 1740, the Bavarian elector Charles Albert immediately repudiated his earlier acceptance and claimed the Habsburg inheritance for himself; Frederick II of Prussia, three months into his reign, invaded Silesia without warning; France joined Bavaria; Britain, the Dutch Republic and the empire's smaller estates supported Maria Theresa. The War of the Austrian Succession (1740–1748) was the result.
The war produced two principal outcomes. The first was the loss of Silesia by the Habsburg crown to Prussia, confirmed at the Peace of Aachen in 1748. Silesia was the wealthiest and most industrialised province of the Habsburg inheritance; its transfer to Prussia approximately doubled the Prussian state's economic base, and Maria Theresa would spend the rest of her reign attempting to reverse the loss. The second was the Bavarian Charles Albert's brief tenure as Emperor Charles VII (1742–1745) — the first non-Habsburg emperor since 1438 — followed by his death and the return of the imperial title to Maria Theresa's husband Francis Stephen of Lorraine, who reigned as Francis I (1745–1765). The Habsburg dynasty thereby became the Habsburg-Lorraine dynasty; the imperial title returned to the family but through the female line.
The Seven Years' War
Maria Theresa's attempt to reverse the Silesian loss produced the Seven Years' War (1756–1763), the largest European war between the Westphalian peace and the Napoleonic Wars. The diplomatic preparation — the famous Diplomatic Revolution of 1756, engineered by the Habsburg chancellor Kaunitz — reversed the previous century's alliance system: France allied with Austria (their first formal alliance in 300 years), Britain with Prussia. The war's continental theatre saw a Prussian army of about 200,000 fighting an Austrian-Russian-French-Saxon coalition of approximately 500,000 across central and eastern Germany; Frederick II's defensive operational virtuosity (the battles of Rossbach, Leuthen, Zorndorf, Kunersdorf) kept the Prussian state in the war through five years of compounded defeats, but by 1762 the Prussian position was effectively collapsing. The accession of Tsar Peter III of Russia in January 1762 — a personal admirer of Frederick — produced the immediate Russian withdrawal from the war (the "Miracle of the House of Brandenburg") and allowed Frederick to recover his position. The Peace of Hubertusburg of 1763 restored the pre-war territorial status quo. Silesia remained Prussian; Maria Theresa's twenty-three-year project had failed.
The war's structural significance was that it demonstrated that Prussia was now a major European power, capable of surviving a coalition of all the major continental states. The empire's institutional response — the imperial estates' attempt, through the imperial military levy, to support the Habsburg side — had been ineffective and embarrassing; the imperial army at Rossbach in 1757 was famously defeated in ninety minutes by a Prussian force half its size. The lesson the smaller imperial estates drew was that the imperial defensive system could no longer be relied upon. The principal estates (Bavaria, Saxony, the ecclesiastical electorates, the Westphalian principalities) would increasingly look to bilateral diplomacy with the major external powers rather than to the imperial diet for their security guarantees.
The reformist decade
The forty-year reign of Maria Theresa (1740–1780, with Francis I as nominal emperor 1745–1765 and her son Joseph II as co-regent 1765–1780) was the great reformist period of the Habsburg monarchy. The administrative and judicial reforms of the 1740s and 1750s (the Theresian codes, the standing standing army reorganisation, the Court Chancery reforms, the public-finance reforms) converted the Habsburg state from a loose collection of medieval estates into a centralised early-modern monarchy. Joseph II (1780–1790) accelerated the programme with an even more radical Enlightened-absolutist agenda: the Patent of Toleration of 1781 (granting religious toleration to Protestants and Orthodox), the abolition of serfdom (1781 in Bohemia, extended progressively), the Josephinist church reforms (closure of contemplative monasteries, replacement of papal jurisdiction with state oversight), the standardisation of administration in German across non-German territories (which produced substantial Hungarian and Bohemian resistance), and the centralisation of the judiciary. The reforms were partially rolled back by Joseph's brother Leopold II (1790–1792) under pressure from estate resistance, but the Theresian-Josephist administrative state was a permanent legacy.
Joseph II's reformism extended to the empire as well, particularly to his attempt to acquire Bavaria through exchange with the Wittelsbach Palatinate (the proposed Bavarian-Belgian exchange of 1785, which Prussia and the smaller German states blocked through the Fürstenbund of 1785). The episode confirmed that the empire's smaller estates would resist Habsburg consolidation as much as they had resisted Prussian aggression — the principle of imperial constitutionalism cut against both major powers. But the resistance was institutional rather than military, and the imperial constitution's capacity to defend the empire's territorial integrity in the face of a serious external threat was about to be tested.
The 1780s and the eve of the Revolution
By the late 1780s the empire's external situation appeared, paradoxically, secure. The Ottoman threat had been resolved by Eugene's reconquests a century earlier; the French monarchy was visibly approaching fiscal-political collapse; the Austro-Prussian dualism was held in equilibrium by the Fürstenbund of 1785 and by the mutual exhaustion of the Seven Years' War. The imperial diet at Regensburg processed routine business. The free cities continued in their civic autonomy. The prince-bishoprics governed in the slow ecclesiastical-aristocratic style they had perfected over two centuries. Nothing in the institutional structure of the empire in 1788 suggested that it had eighteen years left.
The French Revolution of 1789 was, in the empire's official self-understanding, a French problem. The revolutionary government's progressive radicalism through 1791–92, the emigration of the French aristocracy into the Rhineland prince-bishoprics, the Declaration of Pillnitz of August 1791 (the Habsburg-Prussian joint declaration in favour of restoring the French monarchy), and the French declaration of war on the empire in April 1792 transferred the revolutionary crisis directly to imperial territory. The empire's response, the campaign that produced the catastrophes of the next decade, is the subject of the next chapter.
End of Chapter VII