The castle already existed in 1271, was mentioned by D. Afonso III in his donation letter to Infante D. Afonso. The urban wall also existed in 1274, with doors. The wall and the Castle will have been reinforced after the prolonged siege that D.Dis made to the infant D. Afonso to recover Portalegre for the crown. The castle maintains its 3 towers, which were connected by walls. The intermediate room in the Keep has a Manueline vault, with chamfered ribs, forming a four-pointed star, with bits decorated with the Cross of Christ and plant motifs, displaying the royal shield on the clasp. The tower that reached the highest altitude is located to the north, it is massive up to the level of the adarve, with only a vaulted and cracked room, accessible by a single Roman style door (imposed with a concave cut and tympanum with low relief from the flaming sun) . There was a takeover of this castle by the population in 1387, revolted against its mayor D. Pedro Álvares Pereira, who had taken the Castilian side.