Which 1755 earthquake destroyed much of Lisbon, Portugal, and generated a tsunami?

The 1755 Lisbon earthquake destroyed much of Lisbon, Portugal, and generated a tsunami.

The earthquake struck on 1 November 1755, All Saints’ Day, and was followed by fires and tsunami waves. Lisbon suffered catastrophic destruction, while coastal areas of Portugal, Spain, and Morocco were also affected. Estimates of its magnitude vary because modern instruments did not exist at the time.

The event was felt across a very large area and became one of the most studied disasters of eighteenth-century Europe. Its destruction influenced discussions about urban rebuilding, disaster response, and the relationship between natural events and society.

The earthquake’s exact source remains uncertain, but it is generally associated with a large offshore rupture in the region west or southwest of Portugal. It should not be confused with later earthquakes in Lisbon, including the damaging 1969 event.