The League of Nations, the international organization formed at the peace conference at Versailles in the wake of World War I, recognizes the perpetual neutrality of Switzerland on February 13, 1920.

Switzerland was a loose confederation of German-, French-, and Italian-speaking communities until 1798, when the French, under Napoleon Bonaparte, conquered and unified the country as the Helvetic Republic and imposed a constitution, which was enforced by French occupation troops. Bitterly resented by the Swiss people, the French occupation ended in 1803, when Napoleon agreed to a new Swiss-approved constitution and withdrew his troops. The Congress of Vienna in 1815, which would determine Europe’s borders until the outbreak of World War I nearly a century later, recognized the perpetual neutrality of Switzerland.

The Swiss considered preserving this neutrality essential to Switzerland’s economic and political development. A new constitution, adopted in 1848, reinforced the neutrality principle by outlawing Swiss service in foreign armies or the acceptance of pensions from foreign governments. Neither the unification of Italy in 1861 nor the birth of the German empire in 1871 shook the loyalty of the nation’s Italian or German population to Switzerland. With industrialization, fueled largely by hydroelectric power, and the construction of an efficient railroad network, Switzerland’s economy continued to grow, spawning a thriving tourism industry by the end of the 19th century.

Though Switzerland maintained its neutrality during World War I, with German, French and Italian Swiss standing firm to preserve their country’s solidarity, a costly military mobilization to protect the Swiss borders diverted most of the working population to war-related work and brought economic hardship. After the war ended, membership in the League of Nations—the international organization established at the Versailles peace conference—was narrowly approved by Swiss voters after a federal council opposed it. In February 1920, the League voted to recognize the perpetual neutrality of Switzerland. The League also established its headquarters in the Swiss city of Geneva, a tribute to the country’s neutrality as well as its relative economic and political stability, which has continued to the present day.