The Thirty Years War and French Ascendancy

Richelieu's foreign policy demonstrated raison d'état's triumph over confessional solidarity. Despite his cardinal's rank, he allied Catholic France with Protestant powers against the Catholic Habsburgs. This policy, shocking to contemporaries, showed monarchy's interests transcending religious allegiance. The results transformed European balance of power in France's favor.

French intervention in the Thirty Years War (from 1635) initially brought military disasters. Spanish invasions reached Corbie (1636), threatening Paris itself. Yet patient rebuilding of military forces, improved logistics, and superior financial resources gradually shifted advantage to France. Victories at Rocroi (1643) and elsewhere demonstrated French military resurgence. Though Richelieu died before war's end, his strategic vision proved sound.

The Treaty of Westphalia (1648) confirmed French gains: Alsace, strategic fortresses, and effective hegemony replacing Spanish dominance. More subtly, the treaty's recognition of state sovereignty over religious authority validated Richelieu's prioritization of state interests. The European state system emerging from Westphalia reflected French rather than Habsburg concepts of political order.

Military reforms underpinned diplomatic success. The expansion of permanent forces, improved artillery, and systematic logistics created Europe's most formidable army. Noble military service, channeled into royal armies rather than private forces, maintained aristocratic honor while serving state purposes. Military academies trained officers in technical skills beyond traditional noble courage. These reforms created the instrument of Louis XIV's future conquests.