[7] On 13 September 1297, when Beatrice was only four years old, the bilateral agreement, known as the Treaty of Alcañices, was signed between Castile and Portugal, putting an end to the hostilities between both kingdoms and establishing the definitive borders.

The treaty was signed by Queen María de Molina, as the regent of Castile on behalf of her son, Ferdinand IV, who was still a minor, and King Denis of Portugal.

[12] Her future father-in-law "had inherited from his grandfather, Alfonso X of Castile, a love of letters, literature, Portuguese poetry, and the art of the troubadours" and Beatrice grew up in this refined environment.

In 1301, Pope Boniface VIII issued the papal bull authorizing the marriage, but since both were underage, it was postponed until 1309 when Afonso was eighteen years old and Beatrice had turned sixteen.

[2] While the definitive tombs were being built, the royal couple was originally buried at the choir of the church and it was not until the reign of King John I that their remains were transferred to the new sepulchers in the main chapel of the cathedral.

The Livros do Cartóiro da Sé (Charters of the cathedral) written between 1710 and 1716, describe the burial of Queen Beatrice, very similar to that of her husband, with an engraving that read: Beatriz Portugaliae Regina / Affonsi Quarti Uxor.