Castle of Campo Maior

The Castle of Campo Maior is a medieval fortress on a low hill in Portugal's Alentejo, close to the Spanish border. For centuries it guarded the approach to the country as part of a first line of defence that also included Ouguela, Elvas, Olivença and Juromenha. Today it is one of the region's most interesting military monuments, and its story culminates in a dramatic event of the 18th century.

Where is the castle and why was it built?

The town of Campo Maior lies in eastern Portugal, in the Portalegre district, a short distance from the Spanish frontier. The first fortification on the hill may have been raised by the Moors. During the Reconquista the settlement was taken in 1230 by the forces of Alfonso IX of León. The Portuguese captured it in 1295–1296, and in 1297 the Treaty of Alcanizes formally made it part of Portugal.

How did the castle develop?

In 1310 King Denis ordered the fortress rebuilt to help keep the peace with the neighbouring kingdom. In the late 15th century John II began enlarging it, and his successor Manuel I completed the work. A Manueline window in the north tower, since recovered, dates from this phase.

In the mid-17th century, during the war of Portuguese independence, John IV strengthened the castle and adapted it to modern warfare. The defences withstood a Spanish siege in 1712 that lasted 36 days and failed, though it caused serious damage.

What happened in 1732?

Around 3 a.m. on 16 September 1732, during a thunderstorm, lightning struck the armoury in the main tower, which held huge stocks of gunpowder and ammunition. The explosion and fire killed about two thirds of the townspeople, an estimated 1,500 people. The devastation left a lasting mark on the town's memory.

What can you see today?

You can walk around the outer walls and bulwarks at any time, and it is worth looking for the Manueline window in the north tower. The inner complex and the interpretive centre can be visited only on a guided tour.

The victims of the explosion are remembered in the Capela dos Ossos, the Chapel of Bones, next to the Igreja Matriz parish church, where their remains are displayed. It is a striking place and a fitting complement to a castle visit.

Frequently asked questions

Can I visit without a guide? You can see the outside walls and bastions freely at any time. Entry to the interior and interpretive centre is by guided tour only.

Who rebuilt the castle in 1310? King Denis ordered the work, aiming to secure peace with Portugal's neighbour.

What destroyed the castle in 1732? Lightning hit the powder store in the main tower, causing a huge explosion and fire.

What else is nearby? The fortified village of Ouguela and the city of Elvas belonged to the same defensive system. In Campo Maior itself, do not miss the Chapel of Bones.

Which defensive system did the castle belong to? The first line of Alentejo defence facing Spain, alongside Ouguela, Elvas, Olivença and Juromenha.

The castle combines several eras: medieval reconstruction, Manueline decoration and bastioned reinforcement from the wars of the 17th century. For anyone interested in the Iberian borderlands, it helps explain what life was like in a fortress town. A walk along the walls also offers a view over the Alentejo plain, from which defenders once watched for approaching armies. Plan your visit together with the nearby fortresses, and leave time for the guided tour, since the interior tells the story of 1732 most fully.