During an All Saints’ Day mass in Lisbon in that fateful year, an 8.5-magnitude earthquake collapsed cathedrals, triggered a 20-foot tsunami, and sparked devastating fires that destroyed nearly 70% of the city’s 23,000 buildings.
The death toll was estimated between 10,000-50,000, leaving the center of a global empire in ruins, with losses equivalent to 32%-48% of Portugal's GDP at the time.
Never in the European history had a natural disaster received such international attention.
The “Great Lisbon Earthquake” had a resounding impact across Europe: Depictions of the earthquake in art and literature – the equivalent of today’s mass media – were reproduced for centuries and across several countries. Rousseau, influenced by the devastation, argued against large and dense cities in the wake of the disaster, while Immanuel Kant published three separate texts on the disaster, becoming one of the first thinkers to attempt to explain earthquakes by natural, rather than supernatural, causes.
In the years to follow, careful studies of the event would give rise to modern seismology.