The castle of A Rocha Forte was the outside projection of the Cathedral-fortress of Santiago, the true ecclesiastic, administrative and military headquarters of the domain of the archbishops of Santiago. Throughout the 13th and 14th centuries new construction elements are added to improve its defenses. These changes began with Archbishop Rodrigo de Padrón, but became more marked with Berenguel de Landoira.
The differences between the alterations by one or the other archbishop were also symbolic as Berenguel had a more offensive approach and built a number of towers at strategic locations to protect the building and underscore its outside image of might. While Rodrigo de Padrón sought to improve the protection of the cathedral and its treasures, Berenguel turned the cathedral into a true fortress going from passive to active defense.
The construction of the fortress in Santiago is not an isolated fact but it is reflected in other cathedrals of the time, like Tui’s. It also in line with the changes to military architecture: moving from the Romanesque to the Gothic fortress and to active defense, which meant a number of changes and alterations to the Galician castles of the time.