Owing the regions occupation by successive tribes of Celts, Romans and Muslims, it is likely that the territory of Campo Maior has been settled during the pre-historic epochs.

[1][2] These fortifications were extended and rehabilitation during the 15th and 16th century completed, during the reigns of his successors John and Manuel, designed by Duarte d'Armas.

[1] Between 17th and 18th century the fortification was adapted for the time, obtaining the bulwarks and secondary walls, in addition to the installation of permanent military storehouses, stables and barracks.

The powder magazine was reconstructed by order of John V of Portugal in 1735, under the meticulous care of Manuel de Azevedo Fortes.

[1][2] On 2 July 1736, Diogo Lopes de Sepúlveda was awarded the commission to the post of Sergeant-Major, as part of his efforts in reconstructing the square after these events.

In the first half of the 1940s, the Direcção-Geral dos Edifícios e Monumentos Nacionais (DGEMN) began works to restore the group of structures.

A second phase of construction was begun in the 1960s, and extended into the 1970s, marked by interventions in the castle walls and the Chapel of Nossa Senhora dos Aflitos.

[2] It is positioned, 10 kilometres (6.2 mi) from the Spanish frontier and 18 kilometres (11 mi) from Badajoz and Elvas (areas that are visible from its towers), the fortress is encircled in the north, northeast, east and southeast by modern buildings and the town is similarly encircled by agricultural lands.