Huge earthquake occurred on All Saints Day while many of the 250,000 inhabitants of Lisbon were in Church. Even though not the strongest or most deadly earthquake in human history, the 1755 Lisbon earthquake’s impact, not only on Portugal but on all of Europe, was profound and lasting. Stone buildings swayed violently and then distorted on the population. Many who sought safety on the river front were drowned by a large tsunami.

The fluctuation of balanced objects at great distances from the epicenter indicates an enormous area of perceptibility. The observation of seiches as far away as Finland, suggest a magnitude approaching 9.0. Precursory phenomena were reported, including muddy waters in Portugal and Spain, falling water level in wells in Spain, and a decrease in water flow in springs and fountains. Depictions of the earthquake in art and literature can be found in several European countries, and these were produced and reproduced for centuries following the event, which came to be known as The Great Lisbon Earthquake.