Archaeological work completed researchers from the University of Minho discovered a defensive wall, consisting of polygonal plan, reinforced by small semi-circular turrets, dating to the 3rd century.

[2] Recent information points to polygonal plan, defined by rectilinear lines that crossed the structure, with an area between 40 and 50 hectares, punctuated by semi-circular towers .

[3] During the period of Iberian migration, the Suebi chose Bracara Augusta as the capital of their kingdom due to its strategic importance and settlement.

However, the early settlements floundered with successive conquest, under the Visigothic tribes, southern Moorish invaders and the Christian Reconquista of the Kingdom of León.

[1] It was in 1300, that King Denis ordered the construction of the castle, as noted by Monseigneur José Augusto Ferreira, and a year later the budget was applied to the project.

[1] Yet, by 31 August 1398, the archbishop D. Martinho Pires da Charneca obtained license from King John I to repair the castle and nominate an alcalde.

By 20 November, of the same year, the same archbishop solicited Cabido 2000 corner stones from the tower of Quintã de Carapeços for public work on the castle and archiepiscopal.

[1] On 20 December 1421, the king determined that the Moorish residents that did not respect the contract between the prelate, cabido and population, should be obliged to pay 100 reis fine, which was then applied to the construction of the walls.

[1] They attributed these complaints to the King's uncle, Afonso, 1st Duke of Braganza, who was the project's comptroller, and public works in the comarca of Entre Douro e Minho.

[1] These continued problems forced King Afonso V on 12 March 1472, to restore the authority over the city and jurisdiction to archbishop Luís Pires.

[1] Inevitably, the Church began the reconstruction of the defenses; by 1477, the wall tower, alongside the Gate of São Tiago, was already underway, requiring the collection of taxes on the sale of properties in the city.

[1] The Direcção Geral dos Edifícios e Monumentos Nacionais (DGMEN) began the first efforts to recuperate the Castle's remains in 1942–1943, with remodelling of the keep tower, roofing the space and coverage, assessment of pavements, replacement of doors and frames, the clearing of space around the courtyard, including the demolition of existing local structures, and replacing cornerstones that were damaged.

[1] In 1956, the roof was repaired, including the substitution of broken tiles, repairs to the battlements, frames, and substitution of broken windows, while another group of public works was made to transition the structure for reuse, such as the installation of an electrical system, arrangement and painting of the door, construction of a new staircase, and the re-landscaping of the terrain around it, including leveling the terrain, paving with gravel and planting flowerbeds.

[1] Of the old castle only the keep tower (Portuguese: Torre de Menagem) remains, consisting of a rectangular footprint and vertical block covered in tile.