1720 was a year of sharp contrasts: speculative fever and financial collapse in several countries, a devastating outbreak of plague in southern France, and diplomatic agreements that brought an end to long-running conflicts in parts of Europe. Political, economic and public-health developments during this year had effects that lasted for decades.

Economic crises: bubbles and legislation

Two linked financial manias reached their peaks and then collapsed in 1720. In France the system promoted by the banker John Law and the Compagnie des Indes (often called the Mississippi scheme) expanded credit and speculative investment before imploding. In Britain the South Sea Company’s takeover of large amounts of government debt and the associated stock speculation produced a comparable boom-and-bust episode, the South Sea Bubble. The crisis prompted government action to restrain corporate speculation, including tighter control over joint-stock companies.

Plague of Marseille

In the summer of 1720 a major outbreak of bubonic plague struck the port city of Marseille and surrounding Provençal towns. The epidemic — brought to Europe by infected ships from the eastern Mediterranean — led to quarantine attempts, civic emergency measures and thousands of deaths. The Marseille plague is often cited as the last large-scale urban plague outbreak in Western Europe.

War, diplomacy and political consequences

Across Northern and Western Europe 1720 saw the negotiation and signing of peace settlements that wound down fighting remaining from earlier 18th-century conflicts. Several treaties and diplomatic accords adjusted boundaries, confirmed new power balances and returned many combatants to peacetime commerce and diplomacy. The end of hostilities helped shift attention toward economic reconstruction and colonial competition.

Culture, science and long-term effects

Although overshadowed by crisis, cultural and scientific life continued; literary, artistic and scientific exchanges proceeded across Europe. The twin financial collapses influenced later debates about banking, public credit and government finance, while the Marseille epidemic shaped public-health responses and quarantine practices in port cities for generations.

  • Major themes: speculative finance, public-health crisis, diplomatic settlement.
  • Legacies: reforms in financial regulation, quarantine policy, altered European diplomacy.