The 1755 Lisbon earthquake and the city that rose after it

A feast-day morning by the river

On the morning of 1 November 1755, an earthquake lasting about six minutes shook Lisbon. The Baixa, the flat lower town beside the Tagus, was among the worst-hit areas. The quake was followed by a tsunami and then by a fire that burned for days.

Picture the waterfront as it was. Where Praça do Comércio (Commerce Square) opens out today stood the Terreiro do Paço, literally the palace yard: the royal palace, the customs house, the Casa da Índia, the Mint, the arsenal and an opera house that had opened only months before the disaster. Behind it lay a maze of medieval streets, their shops full of goods from the trade with the Indies.

The royal family, as it happens, weren't there. They were at their estate in Belém, downriver, and it held.

Seen and heard

The Englishman with the letter was the Reverend Charles Davy. He describes the walls of his house splitting open, big stones coming down and beam-ends pushing out through the roof. He made his way through narrow streets of collapsed houses, clambered over the ruins of the church of São Paulo to the riverbank, and there saw a mass of water coming in "like a mountain". He survived by clinging to a beam.

Davy also gives us one of the best-known images of the disaster: a fine new quay, built entirely of marble, swallowed by the river along with the people who'd taken refuge on it. And here's what makes his letter so valuable: he admits he didn't see it. Some ships' captains told him. Days later he went to look and found nothing but deep water.

Which quay was it? We don't know. Davy places it a few stones' throws from where he was, near São Paulo; putting a name to it would be guesswork. When people tell the story of a disaster, the temptation to embellish is enormous. A witness who keeps what he saw apart from what he was told is worth his weight in gold.

Fire from the candles

Davy had his own explanation for the fire. It was All Saints' Day, every altar in every church was lit with candles, and they set curtains and fallen timber alight. That's his interpretation, and he adds other causes himself. By nightfall, he writes, the city was burning "in a hundred different places", so brightly that you could read by it. The fire went on for six days.

There was a cruel irony, too: the great Royal Hospital of All Saints, where Praça da Figueira is today, was destroyed on All Saints' Day itself.

How many people died? You deserve an honest answer: the sources we've read give no firm figure, and we'd rather not repeat round numbers we can't stand behind.

Clear it all and draw it again

In 1756 the Casa do Risco was set up (risco means a plan or drawing): a team of military engineers including Manuel da Maia, Eugénio dos Santos and Carlos Mardel. Several proposals were put forward, and the king's minister, the future Marquis of Pombal, opted for the boldest: clear what was left of the Baixa and lay it out from scratch. Eugénio dos Santos drew a grid of eight streets running south to north and nine running east to west. That's why, on a map, the Baixa looks like a board laid down among the hills.

The old palace yard became a royal square open to the river. It's been called Praça do Comércio since a decree of 1759, and its buildings were paid for by the merchants. In the middle, the equestrian statue of King José, by Machado de Castro, was finished in 1775.

The arch on Rua Augusta, the grand gateway to the new Baixa, was designed back then but not completed until over a hundred years after the earthquake; sources disagree on the exact year. Among its statues, alongside Vasco da Gama, Viriato and Nuno Álvares Pereira, stands Pombal himself. Not a bad spot for the minister who had the place rebuilt.

The cage hidden in the walls

The most interesting thing about the Baixa is the part you can't see. The rebuilding regulations required a timber framework inside the walls, tied to the floors (the gaiola pombalina, or "Pombaline cage"), and firewalls between buildings, so that houses would behave better when the ground shook.

In its 2017 bid to UNESCO, Portugal calls the gaiola "the most advanced anti-earthquake system of the 18th century". That superlative belongs to the applicant, so take it with a pinch of salt.

Now for the twist. At the archaeological site beneath a bank on Rua dos Correeiros, about four metres down, lie the Pombaline foundations: a lattice of timber resting on green-pine stakes sunk into the groundwater. But the same site also turned up a 16th-century house that already stood on wooden piles. The solution wasn't invented after the earthquake. Lisbon already knew it.

The ruin someone decided to keep

Up in Chiado, the roofless arches of the Carmo look like the church exactly as that morning left it. They aren't. Ruined in 1755, it was being rebuilt in neo-Gothic style until work stopped in 1834, when the religious orders were abolished, and 19th-century Romantic taste decided the naves looked better open to the sky. The arches you see belong to that unfinished rebuild, not to the Middle Ages.

Divine punishment or natural causes?

The earthquake shook ideas, too. Against the official explanation of natural causes, a Jesuit with influence at court, Gabriel Malagrida, published a pamphlet blaming it on divine punishment for the sins of the court and the city. Shortly afterwards, in Candide (1759), Voltaire mocked the Portuguese wise men who could think of nothing better to prevent further earthquakes than an auto-da-fé.

Nobody would have scripted the ending this way: in 1761 Malagrida himself became the last person put to death by the Inquisition in Portugal, executed in the Rossio. But that story has a stop of its own.

Fact or legend.

• Fact: the earthquake of 1 November 1755, the tsunami and a fire lasting several days; the rebuilding with a grid and the gaiola.
• Hearsay: the marble quay swallowed by the river. Davy tells it but warns he didn't see it, and we don't know which quay it was.
• A line with no safe owner: "bury the dead and care for the living" is often pinned on Pombal, but the attribution is disputed and we haven't found where it first appears. We won't put it in his mouth.
• Nothing to back it up: that Alfama came through intact, or that the earthquake moved the river away from Belém Tower. We haven't found either documented; at Belém, everything points to the shoreline creeping forward with landfill.

Where to hear it

This story is told stop by stop on Lisbon's Baixa: from Terreiro do Paço to the Rossio, Podtour's free route in Lisbon: eleven stops, mostly flat and all in the open air. It starts at the Cais das Colunas with Davy's letter, then takes you to the Casa do Risco in front of King José's statue, the Rua Augusta arch and the wooden cage inside the Baixa's walls. The Carmo ruins feature on Chiado and Bairro Alto; the hospital lost on All Saints' Day and Malagrida's last pyre, on From the Rossio to the Mouraria.

Further reading

• Charles Davy, 'The Earthquake at Lisbon, 1755', a letter published in his Letters (1787); Eva March Tappan's edition (1914) in the Internet History Sourcebooks, Fordham University. https://sourcebooks.fordham.edu/mod/1755lisbonquake.asp
• Património Cultural (DGPC), inventory record for Praça do Comércio (in Portuguese). https://imovel.patrimoniocultural.gov.pt/detalhes.php?code=70275
• Permanent Delegation of Portugal to UNESCO, 'Pombaline Lisbon', Tentative List (2017). https://whc.unesco.org/en/tentativelists/6226/
• Fundação Millennium bcp, Rua dos Correeiros Archaeological Site (NARC). https://fundacaomillenniumbcp.pt/en/nucleo-arqueologico/
• Museu Arqueológico do Carmo, history of the ruins and the museum. https://museuarqueologicodocarmo.pt/mac_en.html
• Voltaire, Candide, ou l'optimisme (1759), chapter VI, Project Gutenberg (in French). https://www.gutenberg.org/cache/epub/4650/pg4650.txt