History of São Jorge Castle: Iron Age to Now

São Jorge Castle crowns the highest hill in Lisbon’s historic centre, and almost every wave of the city’s past has left something on this ground. People have fortified the summit since the Iron Age, and the walls you climb today are the work of Moorish engineers nearly a thousand years ago. Between then and now the hill has been a Roman settlement, a Muslim citadel, a Christian royal palace and, eventually, the restored landmark that draws you up the cobbles.

This guide walks through that story in order — from the earliest hilltop settlement to the Moorish fortress, the 1147 conquest, the centuries as a royal palace, the long decline after the court left, and the 20th-century restoration that gave us the castle you visit today.

São Jorge Castle History at a Glance

An Iron Age Hilltop

The story begins long before any castle. The summit of São Jorge hill was settled and fortified in the Iron Age, its steep flanks and command of the Tagus estuary making it an obvious defensive site. Later came the Romans, who occupied the hill as part of their city of Olisipo, and after them the Visigoths. Each left traces in the ground rather than in the walls, and you can still see some of the oldest layers exposed in the archaeological site inside the castle.

What survives above ground, though, belongs to a later age. By the time the first stones of today’s fortifications were laid, the hill had already been a stronghold for well over a thousand years.

The Moorish Fortress

Lisbon spent centuries under Muslim rule, and it was in that period — the mid-11th century — that the fortress took the form we recognise. The Moorish builders raised the citadel at the very top of the hill, an inner stronghold above the wider walled town, sheltering the governor and the ruling class. The eleven towers, the curtain walls and the fortified gates all trace back to this design.

This is why the castle can feel older and plainer than a fairy-tale European fortress: it was built for defence and control, not display. Walking the ramparts and towers today, you are following lines drawn by Moorish engineers who never imagined a Portuguese king would one day hold the keys.

The 1147 Conquest

The turning point came in 1147. Dom Afonso Henriques, who had declared himself Portugal’s first king a few years earlier, marched on Lisbon and laid siege to the Moorish city. He was aided by a fleet of Northern European crusaders — including English, Flemish and German fighters — who had stopped in Portugal on their way to the Second Crusade. After roughly four months, the city fell, and the citadel on the hill passed into Christian and Portuguese hands.

The conquest reshaped the map of the peninsula and gave the new kingdom its greatest city. The old Moorish citadel, taken almost intact, became a royal stronghold overnight. A bronze statue of Afonso Henriques still stands on the castle’s parade ground, the Praça de Armas, marking the man who claimed it.

A Royal Palace: the Paço da Alcáçova

For the next few centuries the castle was not just a fortress but a home for kings. From the 13th to the early 16th century it served as the royal palace, known as the Paço Real da Alcáçova, where Portuguese monarchs lived, held court and received ambassadors. This was the castle at its grandest — the political heart of a kingdom that was beginning to send ships across the oceans.

Little of that palace survives in one piece, but its footprint remains. The medieval palace ruins on the site let you trace where the royal halls once stood, and the permanent exhibition displays objects excavated from these layers, from tableware to fragments of everyday palace life.

Dedicated to St George

The castle owes its name to a moment in the late 14th century. Under King João I, the fortress and its patronage were dedicated to St George — São Jorge — the warrior saint. The choice reflected the growing Anglo-Portuguese alliance, sealed by João’s marriage to Philippa of Lancaster, an English princess. St George was already the patron saint of England, and adopting him bound the two crowns together in a shared symbol.

The name stuck, and it has outlasted the palace, the court and the kingdom itself. Every visitor who climbs the hill today is, in a small way, still honouring a medieval diplomatic marriage.

Decline and the 1755 Earthquake

The castle’s golden age ended when the court moved down to the riverside in the early 16th century, drawn by the new palace on the Terreiro do Paço and the bustle of the docks. Stripped of its royal role, the hilltop fortress was handed over to the military. It spent the following centuries as barracks and, at times, a prison — useful, but forgotten.

Then came 1 November 1755, when one of Europe’s deadliest earthquakes struck Lisbon, followed by fire and a tsunami. The disaster destroyed swathes of the lower city and damaged the castle heavily. For the next 180 years the fortress crumbled quietly above a city rebuilding itself below.

Restoration and the Castle Today

The castle’s revival came in the 20th century. Between 1938 and 1940 a major restoration cleared away later military additions and consolidated the medieval walls and towers, reshaping the ruin into a monument the public could visit. The work was not a perfect reconstruction of any single era, but it rescued the fortress and reopened its ramparts to the city.

Today the castle is managed by EGEAC, Lisbon’s municipal culture company, and it is one of the city’s most visited sites. Inside the Tower of Ulysses you’ll find the Camera Obscura, a periscope of lenses and mirrors that projects a live image of the city — a modern curiosity layered onto an ancient tower. If you’d like the whole story told as you walk, an entry ticket with audio guide supplies the context, or a live guided tour brings a historian’s eye to the stones.