The Earthquake of 1755

On November 1, 1755 — All Saints' Day, when the churches were full of worshippers — one of the most devastating earthquakes in history shook Lisbon. What followed was a triple catastrophe:

• The earthquake itself (estimated magnitude 8.5–9.0) destroyed large parts of the city within minutes
• The tsunami — waves up to 15 meters high flooded the waterfront and swept thousands to their deaths
• The fire — the overturned All Saints' candles set the debris ablaze; Lisbon burned for five days

Between 30,000 and 60,000 people died in Lisbon alone. Magnificent palaces, libraries, churches, and archives were destroyed. The royal library with 70,000 volumes, including original reports of the explorers, was lost.

Yet out of the catastrophe emerged something new. The Marquês de Pombal, Prime Minister under King José I, organized the reconstruction with remarkable efficiency. His famous saying: "Bury the dead, take care of the living." The Baixa Pombalina, the grid-patterned city center of Lisbon, was one of the first earthquake-resistant construction projects in the world — with flexible wooden structures (gaiola pombalina) that could absorb shocks.

The earthquake also had philosophical consequences: It shook the belief in a God-directed, benevolent world order. Voltaire addressed the catastrophe in "Candide" and questioned Leibniz's optimism. The Lisbon earthquake is considered the birth of modern seismology and a turning point in the European Enlightenment.