1) After Portugal gained independence in 1143, silver coins called bezants were added to the flag to symbolize the monarch's right to issue currency.
2) Over time, the coat of arms degraded and the cross shape was lost, leaving five escutcheons where the bezants had been. King Sebastian later reduced the number of bezants in each escutcheon to five.
3) During the reign of Afonso III, a red border with golden castles was added to represent the Moorish castles conquered during the Reconquista, though the number of castles varied before being fixed at seven by Sebastian I.
2. Escutcheonsand bezantsAfter the official recognition of the Kingdom of Portugal as an independent country in 1143 (it had been declared in 1139), silver bezants were added to the Burgundian flag, symbolising coins and the right the monarch had to issue currency, as leader of a sovereign state.
3. Eventually, and given the enormous dynamism of medievalheraldry, it is believed that the shield degraded and lost some elements in battle, eventually losing the cross format. This is how King Sancho I inherited the shield from his father, AfonsoHenriques , with no cross and five escutcheons (known in Portuguese as quinas), which stood where the silver bezants had been placed.Later, the number of silver bezants in each escutcheon would be reduced from eleven to five by King Sebastian I, and modern explanations interpret them as the five wounds of Jesus Christ, although this is highly improbable.
4. CastlesIt was during the reign of Afonso III that the red border with golden castles (not towers, as some sources state) was added. Although the number of castles could vary between eight to twelve, Afonso IV would define them as twelve and Sebastian I would finally fix them as seven. They supposedly represent the Moorish castles conquered by the Kingdom of Portugal during the Reconquista . Their origin is probably Castilian, but unlike Spanish castles, which usually have their gates colored blue (hence opened), Portuguese castles were always depicted with gold gates (hence closed).
5. Armillary sphereAn important element of Portuguese heraldry since the 15th century, the armillary sphere was many times used in Portuguese colonial flags, mainly in Brazil. It was a navigation instrument used to calculate distances and represents the importance of Portugal during the Age of Discovery, as well as the vastness of its colonial empire when the First Republic was implemented.