The 1755 Lisbon Earthquake
The Quake, the Tsunami, and the Birth of Seismology
- 9 chapters
- 19m
- Earth Sciences
- Free · no sign-up
This audiobook explores the immediate catastrophe and its aftermath through detailed chapters covering the earthquake's impact on buildings and people, relief efforts, and reconstruction projects led by Sebastião José de Carvalho e Mello, known as the Marquis of Pombal. It examines how the disaster influenced economic systems, political structures, and philosophical thinking across Europe, while also tracing the origins of modern seismology through systematic surveys of the damage.
Listeners will discover how this single event reshaped urban planning, scientific understanding, and intellectual discourse in the eighteenth century. This audiobook offers essential insights for anyone interested in natural disasters, scientific development, or European history.
Listen
-
Read this chapter
The quake struck on November 1, 1755, All Saints’ Day. Accounts from the time describe it lasting between three and a half and six minutes, with cracks five meters wide tearing through the heart of the city. Those who survived rushed toward the docks, only to witness the sea pulling back and exposing a muddy plain thick with wrecked ships and lost goods. About forty minutes after the shaking, a massive wave surged into the harbor, moving so fast up the Tagus River that people on horseback had to race for higher ground to escape being swept away. Two more waves followed. Candles lit for All Saints’ Day were knocked over by the tremor, igniting a fire that grew into a raging firestorm, burning for hours and killing people even far from the flames.
The earthquake and its aftermath reached far beyond Lisbon, shaking towns across southern Portugal, especially in the Algarve region. Coastal fortresses there were destroyed by the tsunami, and entire villages were leveled. Most places along the coast suffered heavy damage, though Faro was spared thanks to the protective Ria Formosa lagoon. In Lagos, the waves climbed up the city walls. Towns like Peniche, Cascais, Setúbal, and even Covilhã, deep in central Portugal near the Serra da Estrela mountains, felt the force of the quake and the wave. The shock damaged part of Covilhã’s castle walls and towers, as well as buildings in Cova da Beira and Salamanca, Spain. Setúbal’s Fort of São Filipe de Setúbal also sustained damage.
The earthquake's impact reached far beyond Lisbon, shaking the island of Madeira hard, with Funchal and smaller towns taking serious damage. In the Azores archipelago, nearly all ports were destroyed by the ensuing tsunami, with the sea pushing about 150 metres inland. Towns in northern Africa, like Ceuta and Mazagon, also felt the force, as the waves hit coastal fortifications and flooded harbor areas. In Spain, the tsunami swept across the Andalusian Atlantic Coast, causing damage to the city of Cadiz.
The earthquake’s shocks were felt across Europe, reaching as far as Finland and North Africa, with some reports suggesting even as far as Greenland and the Caribbean. Tsunamis struck along the North African coast, waves as high as twenty meters, and traveled across the Atlantic to hit Martinique and Barbados. A three-meter tsunami struck Cornwall on Britain’s southern shore, while Galway on Ireland’s west coast was also hit, damaging the Spanish Arch section of the city wall. In County Clare, a low-lying land connection was washed away, creating Aughinish Island. At Kinsale, ships were spun around in the harbor, and water poured into the marketplace.
In 2015, researchers determined that the massive tsunami waves from the 1755 Lisbon earthquake reached the coast of Brazil, which was a Portuguese colony at the time. Authorities in Brazil sent letters describing the damage and destruction caused by these enormous waves.
Seismologists have long agreed the earthquake's epicenter lay in the Atlantic west of the Iberian Peninsula, yet its precise spot remains disputed. Early theories pointed to the Gorringe Ridge, some 320 kilometers southwest of Lisbon. But later simulations suggested the true origin had to be closer to Portugal’s coast to match the tsunami’s impact. In 1992, a survey of the ocean floor along the Azores–Gibraltar Transform Fault revealed a 50-kilometer-long thrust fault near Cape St. Vincent. It had a dip-slip throw exceeding 1 kilometer, and may have been the main tectonic feature behind the quake.
-
Read this chapter
In 1755, the city of Lisbon was devastated by a massive earthquake, and economic historian Álvaro Pereira estimated that between 30,000 and 40,000 people died there. Another 10,000 may have perished in Morocco. A study from 2009 looking at reports from November 1st found them unclear and hard to distinguish from later earthquakes on the 18th and 19th. Pereira concluded that the total death toll across Portugal, Spain, and Morocco from the quake, fires, and tsunami was between 40,000 and 50,000 people.
The earthquake destroyed 85% of Lisbon, leveling palaces, libraries, and iconic Manueline architecture. The new opera house, the Ópera do Tejo, burned to the ground just seven months after opening. The Royal Ribeira Palace, near the Tagus river, was destroyed along with its vast royal library and art collections, including works by Titian, Rubens, and Correggio. So too was the palace of Henrique de Meneses, which held 18,000 books. Major churches like Lisbon Cathedral and St Paul’s were damaged, and the Royal Hospital of All Saints burned down, killing hundreds of patients. The tomb of national hero Nuno Álvares Pereira was lost, as were records of Vasco da Gama’s explorations. The Carmo Convent ruins remain today as a reminder. Most of the documentation from the 1722 Algarve earthquake was also destroyed in the fire that followed.
-
Read this chapter
After the earthquake, King Joseph I and the court escaped unharmed, having left Lisbon earlier that morning to attend Mass and fulfill a wish of one of the king's daughters to spend the holiday away from the city. The royal family stayed in a large tented camp on the hills of Ajuda, where the king developed a lasting fear of being indoors. His daughter Queen Maria I later built the Palace of Ajuda on that same site. The prime minister, the 1st Marquis of Pombal, also survived and responded to the disaster with a direct order: "Bury the dead and heal the living." He organized relief efforts, sending firefighters to put out fires and mobilizing workers and citizens to remove corpses. Many bodies were buried at sea beyond the Tagus River, against church wishes. To maintain order, the army was deployed, gallows were set up around the city, and more than thirty people were publicly executed for looting. The military also kept able-bodied citizens from fleeing, forcing them into reconstruction work.
In the year 1760, a plan was put forward to construct a new royal palace in the area known as Campo de Ourique, making it the official royal residence. The idea came from those involved in rebuilding the city after the disaster, but the project never moved forward. There wasn't enough focus or enthusiasm for building such a palace in that particular neighborhood of Lisbon. The plan was eventually dropped, leaving the reconstruction efforts to concentrate on other urgent needs.
Just over a month after the disaster, King Manuel and his prime minister began planning how to rebuild Lisbon. On December 4th, 1755, Manuel da Maia, the realm’s chief engineer, laid out four options for the city's future. The first was the cheapest: rebuilding the old city with recycled materials. The second and third plans called for widening certain streets. The fourth, bolder option, proposed tearing down the entire Baixa quarter and starting fresh with new streets laid out without restraint. That final plan was the one chosen by the king and his minister.
The city was cleared of debris in under a year. The king wanted a new, perfectly planned city and ordered the building of large squares, straight roads, wide avenues, and expanded streets — all part of a new vision for Lisbon.
The Pombaline buildings stand as some of the first structures in Europe designed to withstand earthquakes. Before construction began, small wooden models were tested, and simulated quakes were created by having troops march around them. After the 1755 disaster, Lisbon’s Lower Town was rebuilt according to these new seismic principles, and today it is known as the Pombaline Lower Town, or Baixa Pombalina. Other Portuguese cities, like Vila Real de Santo António in the Algarve, also followed this same approach when rebuilding their own districts.
After the 1755 Lisbon earthquake, Maria I, known as A Pia or "Maria the Pious," established an institution called the Casa Pia in 1780. It was organized by Police Intendant Pina Manique, and its goal was to offer shelter and education to children who needed help. The chaos left by the disaster had created a pressing need for such support, and the Casa Pia was one response to that social crisis.
-
Read this chapter
The quake left deep marks on both ordinary people and thinkers of the time. It struck during a major religious holiday, wiping out nearly every significant church in the city. This caused fear and uncertainty among the citizens of a deeply Catholic nation. Theologians and philosophers immediately turned their attention to the event, trying to understand its meaning. Many saw it as divine punishment, a sign from God. The disaster shook not just the physical world, but how people thought about faith, nature, and their place in the universe.
-
Read this chapter
The 2009 study found that the earthquake wiped out between 32 and 48 percent of Portugal’s GDP. Even with strict controls in place, prices and wages stayed unstable for years after the disaster. At the same time, the rebuilding effort raised wages significantly for construction workers. More importantly, the tragedy offered a chance to reshape the economy and reduce Portugal’s reliance on Britain.
-
Read this chapter
The quake shifted Portugal’s politics forever. The king's favorite, Sebastião José de Carvalho e Melo, had risen from humble roots to become the Marquis of Pombal, but the old nobility saw him as an upstart. He didn’t hide his contempt for them, calling them corrupt and useless. Before 1 November 1755, power battles were constant, but Pombal's calm and effective response to the disaster broke the influence of the aristocratic factions. Yet resentment quietly grew against King Joseph I, reaching a breaking point in 1758 when an assassination attempt was made on the monarch. In the aftermath, the king crushed his rivals, including the Duke of Aveiro and the Távora family.
In 1752, a prophet known as a Sebastianist foretold that a massive earthquake would level Lisbon on All Saints' Day. When the disaster struck exactly on that day in 1755, many people saw it as proof of the prophecy's truth. The event led to a sudden increase in followers of Sebastianism, as believers interpreted the quake as divine confirmation of the prophet’s words.
-
Read this chapter
Overview
Seismology is the scientific study of earthquakes and the waves that travel through the Earth during these events. The word comes from Ancient Greek, with σεισμός meaning 'earthquake' and -λογία meaning 'study of'. This field looks at how seismic waves are generated and move through planetary bodies, as well as the effects of quakes like tsunamis. It also covers other sources of vibration such as volcanoes, glaciers, rivers, and even explosions. Scientists who study this are called seismologists, and they use tools like seismographs to record the Earth's motion over time. These recordings are known as seismograms. A related area is paleoseismology, which uses geological evidence to learn about past earthquakes.
Ancient and classical eras
Scholarly thinking about earthquakes goes back a long way, all the way to ancient times. Some of the earliest ideas about what causes them were written by thinkers like Thales of Miletus, who lived around 585 BCE, and Anaximenes of Miletus, around 550 BCE. Later, Aristotle, writing around 340 BCE, also considered the natural reasons behind these events. In China, around 132 CE, Zhang Heng of the Han dynasty created the first known device meant to detect earthquakes.
Beginnings of modern science
The Lisbon earthquake of 1755 sparked scientific inquiry into earthquakes, with John Michell determining in 1761 that they originate deep underground as waves from shifting rock. Later, Robert Mallet laid the foundation for modern seismology, coining the term itself, and in 1839 a UK committee formed to improve detection methods. James David Forbes created one of the first seismometers in 1842 using an inverted pendulum. By 1857, Mallet was conducting experiments with explosives. In 1889, Ernst von Rebeur-Paschwitz recorded the first teleseismic signal. Fusakichi Omori showed in 1894 that aftershock frequency decreases after a mainshock. Emil Wiechert theorized in 1897 that Earth's interior has a silicate mantle and iron core. Richard Dixon Oldham identified P, S, and surface waves in 1906, finding evidence of a central core. Andrija Mohorovičić defined the crust-mantle boundary in 1909. Harry Fielding Reid proposed the elastic rebound theory after the 1906 San Francisco quake. In 1920, a Wiechert seismograph recorded aftershocks from the Xalapa earthquake. Harold Jeffreys claimed in 1926 that Earth's core below the mantle is liquid. Inge Lehmann determined in 1937 a solid inner core exists within the outer core. Michael S. Longuet-Higgins explained ocean processes behind microseisms in 1950. By the 1960s, plate tectonics emerged as the comprehensive theory of seismic events and geodetic motion.
-
Read this chapter
Overview
From 1640, when the House of Braganza restored Portugal's independence, until 1777 and the end of the Marquis of Pombal's reign, the country was in transition. Though it had been at its peak during the Iberian Union, Portugal's global influence lingered through the era of discoveries. By the end of this time, its empire was in decline, marked by the Távora affair, the 1755 Lisbon earthquake, and the rise of Maria I as queen. The use of Brazilian gold, absolutism, Brazil's movement toward independence, the Methuen Treaty, and the quake all weakened Portugal's standing. As the Dutch and British rose, Portugal shifted its focus from India to Brazil, and later to Africa after Brazil's independence. The early 18th century, known as the Pombaline Era, saw Sebastião José de Carvalho e Melo, Marquis of Pombal, lead wide-ranging reforms under King Joseph I, who was more interested in gambling than ruling. Pombal expelled the Jesuits, crushed the Távora affair, and rebuilt Lisbon after the earthquake. Yet historians argue his so-called enlightenment was mainly about strengthening autocracy, suppressing opposition, and increasing colonial exploitation. After Joseph's death in 1777, Maria I dismissed him and barred him from coming within twenty miles of her.
Background
In 1578, the Battle of Alcácer Quibir ended with King Sebastian's death and the fall of the House of Aviz. His successor, Cardinal Henry of Portugal, was already 70 years old, and after his death, a dynastic crisis erupted. Three grandchildren of Manuel I claimed the throne: Catherine, Duchess of Braganza, António, Prior of Crato, and Philip II of Spain. António was acclaimed king by the people of Santarém on July 24, 1580, but Philip II marched into Portugal and defeated António's forces at the Battle of Alcântara. He was crowned Philip I of Portugal in 1580 and later recognized as official king by the Portuguese Cortes of Tomar in 1581, beginning the Philippine Dynasty. Under this rule, Portugal remained independent in law and government but lost its foreign policy autonomy, becoming tied to Spain's enemies. The Dutch Republic invaded Portuguese colonies across Asia, Africa, and Brazil. When Philip II died, he was succeeded by Philip III (and IV of Spain), who raised taxes and placed Spaniards in Portuguese government posts, trying to make Portugal a Spanish province. This led to revolution on December 1, 1640, when Antão Vaz de Almada, Miguel de Almeida, and João Pinto Ribeiro killed Secretary of State Miguel de Vasconcelos and imprisoned the Duchess of Mantua. John, 8th Duke of Braganza, was acclaimed King of Portugal as John IV by December 2, 1640.
Restoration War
The war Portugal fought with Spain, called the Restoration War, featured several key battles, including Montijo on May 26, 1644, and Ameixial on June 8, 1663, with victories in all of them. King John IV strengthened his forces by creating the Council of War in 1640 and the Junta of the Frontiers in 1641 to manage border defenses. He also ordered upgrades to fortresses using regional taxes, reorganized the army under the Military Laws of King Sebastian, and built strong ties with England. After winning decisively, John sought peace, but Spain didn’t recognize Portugal’s new Braganza dynasty until his son Afonso VI's reign, during the regency of Peter of Braganza.
-
Read this chapter
Overview
In December 1755, Voltaire wrote a poem in French titled Poème sur le désastre de Lisbonne, responding to the devastating 1755 Lisbon earthquake. The 180-line work was published in 1756 and is seen as a fierce literary assault on the idea of optimism. It’s widely considered an introduction to his 1759 novel Candide and reflects his views on the problem of evil.
Background
On 1 November 1755, a massive earthquake destroyed Lisbon, killing between 30,000 and 50,000 people. The disaster shocked Europe and led philosophers to question the nature of God and suffering. Gottfried Wilhelm Leibniz and Alexander Pope had argued that we live in the best of all possible worlds, a view known as philosophical optimism. Pope expressed this idea in his poem with the line “what is, is right.” Leibniz’s belief was met with scorn by Voltaire, who criticized such thinking as empty and fatalistic. The Lisbon quake strengthened Voltaire’s pessimism and deism. He believed the disaster revealed humanity's ignorance and vice, arguing that expecting divine justice was unreasonable.
Structure
Poème sur le désastre de Lisbonne is a poem by Voltaire, written in rhyming couplets with no breaks or divisions across its 180 lines. The work follows a continuous flow, and like many of his other poems, it includes footnotes that help explain ideas such as the universal chain and man's nature. This structure reflects Voltaire’s method of combining poetic form with philosophical inquiry, using the disaster of Lisbon in 1755 as a backdrop for deeper reflection.
Read
Free to download, keep and share. For general information only — not professional medical, legal or financial advice. Please consult a qualified professional.