Trancoso Castle

Trancoso Castle, locally known as Castelo de Trancoso, lies in the town of the same name in the Beiras e Serra da Estrela region in Portugal.

Trancoso Castle rises on a granite hill, dominating the Beira plateau and the historic route connecting the Douro and Mondego valleys. Its strategic location made it one of the most important strongholds on Portugal’s medieval frontier. The earliest fortification here, probably a Mozarabic watch tower, likely dates back to the 10th century, when the region was still contested by Christian and Muslim forces. It was first mentioned in 960.

After Portugal's founding in 1143, King Afonso Henriques strengthened Trancoso as part of his border defenses against León. The town received its first charter from King Sancho I in 1195, and by the 13th century, the castle had been rebuilt in stone. The surrounding walled town, with its eleven gates and square towers, was completed under King Denis (1279–1325), giving Trancoso its current form. The keep of the castle, slightly offset within the enclosure, bears Denis’s coat of arms.

Together with the castles of Guarda, Celorico da Beira, Linhares da Beira, Marialva, and Longroiva, it was part of a chain of fortified mountain towns securing the Beira frontier. Each of these strongholds crowned a high granite ridge, commanding vast views over the surrounding valleys.

Throughout the 14th century, Trancoso played a key role in the conflicts with Castile. In 1385, its garrison fought in the Battle of Trancoso, where Portuguese forces led by Gonçalo Vasques Coutinho defeated a larger Castilian army, a significant victory during the succession crisis that brought John I of Portugal to the throne. The castle remained a royal fortress, garrisoned until the 16th century, when its military importance declined and domestic houses spread along its outer walls.

Architecturally, Trancoso Castle features a polygonal plan with six flanking towers and a central courtyard. The main gate opens between two towers facing east toward the town square, while a postern on the west side provides access to the hillside. The curtain walls, built of local granite, still reach nearly their original height. Inside, foundations of earlier domestic buildings can be seen, along with the cistern that once supplied the garrison.

Today, Trancoso Castle is freely accessible during daytime hours. When I arrived, it was late and the castle had closed for the day. As I slept in town, I was able to take nighttime pictures. The next day, the weather had turned. Sadly, the interior of the keep was under renovation when I visited and thus not accessible. A great castle.

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