[2] At an unknown date, probably around the turn of the 16th century, Álvaro da Costa married Beatriz de Paiva.

Initially, Beatriz de Paiva acted as wet nurse to John, Prince of Portugal, whose birth coincided with that of their eldest son Gil Eanes, however, she stopped lactating after having fallen ill.[2] Álvaro da Costa also carried out important diplomatic activities on the King's behalf.

It was Álvaro da Costa who, in 1506, brought King Manuel the first Golden Rose offered to him by Pope Julius II.

He was entrusted with a final diplomatic mission in 1520: the negotiations for the marriage of the King's daughter, Infanta Beatrice, to Charles III, Duke of Savoy.

[2] He was buried in the Convent of Our Lady of Paradise, in Évora, in an elaborate Mannerist arcosolium sculpted still in Costa's lifetime by Nicolas Chantereine.