Metternich's Fourfold Plan at the Congress of Vienna (1814–15)

Austrian Chancellor Klemens von Metternich architected the post-Napoleonic order on four pillars:

1. Legitimacy: Restore pre-1789 dynasties. Bourbons (France), Habsburgs (Austria/Spain), Romanovs (Russia), House of Orange (Netherlands), Pope (Papal States). "Rightful rulers" = stability.
2. Balance of Power: Prevent hegemony. Strengthen buffer states: Kingdom of Netherlands (N+S), enlarged Prussia (Rhineland/Saxony), Austrian Lombardy-Venetia, Piedmont-Sardinia. France contained but not crushed.
3. Collective Security (Concert of Europe): Great Powers (UK, Austria, Prussia, Russia, later France) pledge regular congresses to manage disputes, suppress revolution, maintain territorial settlement. First test: Congress of Aix-la-Chapelle (1818).
4. Territorial Adjustments (Compensation/Reward): Redraw map: Russia gains Poland (Congress Kingdom), Prussia gains Rhineland/Westphalia, Austria gains N. Italy, UK gains strategic colonies (Ceylon, Cape, Malta, Heligoland). Norway to Sweden.

Goal: Conservative stability against liberalism/nationalism. Worked ~1815–1848 (Concert managed crises), fractured by 1848 Revolutions & Crimean War.