History of the Margem Sul
From Roman fish-salting on the Tagus and Sado estuaries to the Moors who left their castles, the shipyards that built modern Portugal, and the revolution that ended a dictatorship — the south bank’s history in one read.
Updated April 2026Why the South Bank Has Such a Long Story
The Margem Sul has been continuously settled for thousands of years. The two great estuaries — the Tagus to the north and the Sado to the south — gave it sheltered harbours, abundant fish, and access to the Mediterranean and Atlantic trade. Every great power that touched the Iberian peninsula left something behind: Phoenicians, Romans, Visigoths, Moors, the medieval Christian kingdoms, the Age of Discoveries, the dictatorship, the revolution that ended it.
This guide walks the story from the start. Each chapter is short; together they explain why the towns of the south bank look and feel the way they do today — why Sesimbra has a Moorish castle, why Setúbal had Roman fish factories, why Almada has industrial heritage, why 25 April is the date that defines modern Portugal.
Phoenicians, Romans, and the First Industries
The estuaries were a magnet for early Mediterranean traders.
Pre-Roman settlement
The Lusitanian and Celtic peoples lived along the Tagus and Sado estuaries long before Mediterranean contact. Phoenician and Carthaginian traders established posts along the coast from around 800 BC, exchanging Mediterranean goods for tin, copper, and salted fish.
Roman Cetobriga and Salacia
Rome reached the peninsula in 218 BC and brought industrial-scale production to the region. The town of Cetobriga — on the Tróia peninsula across the estuary from modern Setúbal — became one of the largest garum production centres in the empire, salting fish and producing the fermented fish sauce that flavoured Roman cuisine. Ruins of the salting tanks are still visible at Tróia.
Salacia (Alcácer do Sal)
South of Setúbal, Salacia (modern Alcácer do Sal) was another major Roman centre, also focused on salt and fish production. The salt itself was a strategic Roman commodity.
What survives
The Tróia ruins are accessible by ferry from Setúbal. The Setúbal museum holds Roman artefacts. Place names — Setúbal itself derives from "Cetobriga" via "Santúbal" — carry the antiquity in plain sight.
The Moorish Centuries (711–1147)
Four centuries of Islamic Iberia left castles, agriculture, and place names across the south bank.
The Moorish arrival
In 711 AD, Moorish armies crossed from North Africa and within a few years controlled most of the Iberian peninsula. The Margem Sul fell under the Caliphate and later the taifa kingdoms of al-Andalus — specifically the kingdom of Badajoz from the 11th century.
Castles and infrastructure
The defining built heritage of Moorish rule on the south bank survives: Castelo de Sesimbra dominates the ridge above the fishing town; Castelo de Palmela stands on its hilltop in the wine country; the original fortifications at Almada were Moorish too. The Moors also developed irrigation, citrus cultivation, and rice farming — all of which shaped agriculture for centuries afterwards.
Place names
"Almada" is Arabic for "the mine" (from al-ma’dan). Many south bank place names trace to this period. "Alcochete" too is Arabic in origin.
Reconquista — 1147 onwards
King Afonso Henriques retook Lisbon in 1147 with the help of crusaders. The Margem Sul fell to Christian forces in the years that followed. The Order of Santiago — one of the military religious orders — was given administrative control of much of the south bank. Their headquarters at Castelo de Palmela became one of the order’s most important seats in Portugal.
The Age of Discoveries (15th–16th centuries)
Portugal became a global empire and the south bank became one of its industrial backbones.
Lisbon’s shadow
Through the 15th and 16th centuries, Lisbon became the centre of a global empire stretching from Brazil to India to Macau. The south bank, just across the river, became its industrial back yard — shipyards, fishing fleets, salt production, agricultural supply.
Shipbuilding on the Tagus
Shipyards along both sides of the Tagus built the caravels and naus that carried Portuguese explorers across the world. The south bank’s position — sheltered, with deep water and adjacent forests for timber — suited the trade.
Religious and architectural legacy
The wealth of the discoveries funded buildings still standing today. The Convento da Arrábida, built in the 16th century in the natural park between Sesimbra and Setúbal, dates from this era. The Palácio da Bacalhôa in Azeitão — with its blue-tile interiors and Italianate gardens — is a renaissance survivor.
Decline
The Iberian Union (1580–1640), when Portugal was ruled by Spain, ended the most active decades of imperial expansion. Portugal regained independence in 1640 but the empire’s growth slowed.
The 1755 Earthquake and the Long 19th Century
Devastation, recovery, and the slow industrialisation that defined the modern south bank.
The Great Lisbon Earthquake (1 November 1755)
One of the deadliest earthquakes in European history, with magnitude estimated at 8.5–9. Lisbon was devastated; the tsunami that followed swept up the Tagus and into the south bank. Setúbal, Sesimbra, and the coast were heavily damaged. The rebuilding shaped the urban form of much of the region.
Industrial change
Through the 19th century, fishing in Sesimbra and Setúbal grew into industrial-scale fisheries. Setúbal became Portugal’s major canning centre — sardines from the Atlantic packed in olive oil for European markets. Salt production at Alcochete continued, with the salinas (salt pans) shaping the Tagus estuary landscape that survives today.
Wine and cork
The Setúbal Peninsula consolidated its wine-producing identity in this period. The José Maria da Fonseca winery in Azeitão was founded in 1834 and remains in family hands. See our wine guide.
The First Republic (1910–1926)
Portugal abolished the monarchy in 1910 and went through 16 turbulent years of republican government — coups, assassinations, dozens of governments. The instability set the stage for what came next.
The 20th Century — Salazarism and Industrial Growth
Forty-eight years of authoritarian rule shaped modern Portugal — including the south bank’s industrial identity.
The Estado Novo (1933–1974)
António de Oliveira Salazar took power as Prime Minister in 1932 and consolidated the Estado Novo dictatorship in 1933. His successor Marcelo Caetano continued the regime until 1974. Forty-one years of authoritarian rule — censorship, secret police (PIDE), forced labour in colonial wars, suppression of opposition.
Industrial concentration
Despite the regime’s rural and conservative ideology, industry concentrated heavily in the Margem Sul. The Lisnave shipyard at Mitrena (just east of Setúbal) and the Setenave yard further south became major employers. The Quimiparque chemical complex in Barreiro employed thousands. Setúbal’s canning industry continued at scale.
Labour movement
The concentration of industrial workers on the south bank made it a major centre of clandestine labour organising under the dictatorship. Workers at Lisnave, Quimiparque, and Setenave organised against the regime through underground unions and political networks. This story converges with the events of 25 April 1974 — covered in our dedicated 25 April guide.
The colonial wars (1961–1974)
Portugal fought to retain its African colonies — Angola, Mozambique, Guinea-Bissau — through the 1960s and early 1970s. The wars were unwinnable, expensive, and unpopular. Tens of thousands of Portuguese conscripts died; hundreds of thousands more served. The wars exhausted the country and were the proximate cause of the 1974 revolution.
25 April 1974 and Modern Portugal
The bloodless revolution that ended the dictatorship and made modern Portugal possible.
The Carnation Revolution
On 25 April 1974, a coordinated movement of mid-ranking army officers (the Movimento das Forças Armadas, MFA) overthrew the Estado Novo dictatorship in a near-bloodless coup. Within hours of dawn, tanks were in central Lisbon and the regime had fallen. The flower-seller Celeste Caeiro began handing out red carnations to the soldiers; the troops put them in their rifle barrels; the day was christened the Carnation Revolution.
The south bank’s role
The industrial workers of the Margem Sul were one of the major political forces of the early revolutionary period. Lisnave workers, in particular, took collective action in the months following the revolution that helped shape what came next — nationalisations, decolonisation, the slow construction of a democratic constitution. See the dedicated 25 April guide for the full story.
Decolonisation and democracy
The new regime granted independence to the African colonies within a year. Hundreds of thousands of Portuguese settlers (the retornados) returned to a country in upheaval. The constitution of 1976 established a parliamentary democracy. The Communist Party legalised. The right re-organised. The political settlement took years to stabilise.
Joining Europe (1986)
Portugal joined the European Economic Community (now European Union) on 1 January 1986. EU funds and the open European market transformed the country over the following decades — new motorways, expanded universities, the Vasco da Gama bridge (opened 1998), Lisbon’s 1998 Expo regeneration, Portugal’s adoption of the euro in 2002.
Industrial decline and reinvention
The shipyards of Lisnave and Setenave declined through the 1980s and 1990s. Quimiparque eventually closed. Setúbal’s canning industry shrank. The south bank had to find a new identity — partly residential commuter belt for Lisbon, partly tourism and lifestyle destination, partly a centre of new clean industry. The transformation continues.
The Margem Sul Now
Where the south bank sits in 2026 — and what its history continues to shape.
Demographic shifts
Property prices in central Lisbon have pushed buyers across the Tagus in growing numbers. The south bank has absorbed both Portuguese families priced out of the capital and a wave of international buyers from the UK, US, France, Brazil, and beyond.
Regeneration narratives
Industrial sites are being remade. The Quimiparque area in Barreiro is the largest open redevelopment opportunity in greater Lisbon. The old Lisnave waterfront in Almada has been gradually converted to mixed use. The Margem Sul ferry terminals are being upgraded.
Continuity with the past
Sesimbra still lands fish from the same bay. Setúbal still cans and exports. Azeitão still makes Moscatel from vineyards planted centuries ago. The Festas das Vindimas in Palmela in September is a continuous tradition since 1963. 25 April is celebrated every year with concerts, parades, and the songs that played on the radio in 1974. See our festas guide.
The shape of identity
The Margem Sul has its own identity — not just a suburb of Lisbon, not the Algarve, not the rural Alentejo. The combination of working-class industrial heritage, fishing and farming traditions, the natural park and the coast, and the recent international layer makes it one of the most interesting parts of contemporary Portugal to live in.
Where to feel the history physically
Castelo de Palmela and Castelo de Sesimbra for the Moorish/medieval period. Tróia ruins for Roman. Palácio da Bacalhôa (Azeitão) for the renaissance. Convento da Arrábida and the Cabo Espichel sanctuary for religious heritage. The Almada/Cacilhas waterfront for the industrial era. The 25 de Abril bridge itself — renamed in 1974 from "Salazar Bridge" — is the single most legible piece of revolutionary history you can drive across daily.