This defensive structure was improved during the reign of king D. Sancho I (1185 to 1211).
In 1409, during the reign of king D. João I, the defensive structures of the Castle are improved, and the big Donjon is built. The tower would suffer some alterations after 1640, during the Restoration War, with adaptation for the installation of artillery pieces.
Bragança was also stage for the French invasions, nevertheless its munitions and armoury was able to stop the Napoleonic troops.
Classified as National Monument, the Castle has been receiving improvement and conservation works over the years.
The Castle defensive walls involves the historical nucleus of the town, with an area of about 3 hectares. The “cidadela” is marked by the Donjon, with 17 meters on the side and 34 meters high.
On the north side of the walls is located the famous Princesa Tower, which is linked to an ancient legend…
A noble, yet poor, knight was in love with the princess, leaving to assemble a fortune in order to ask the hand of the Princess, and asking her to wait for his return.
For many years the Princess refused all her pretenders, nevertheless her uncle promised her to a friend of his, forcing her to commit, which she peremptory refused.
The uncle decided to do something and one night, disguised as a ghost, he got into the Princess bedroom, pretending to be the ghost of the young man and told her that if she would not accept to get married with her pretender he would be a condemned soul. Yet, even though it was night time, a sun light entered through the second door and revealed her the deceitful uncle.
These doors from that day on got to be known as the “treason door” and the “sun door”." - in: http://www.getportugal.com/