Álvaro da Costa

D. Álvaro da Costa (c. 1470–1540) was a Portuguese fidalgo, diplomat and close advisor to King Manuel I.

He is particularly well-remembered today for having filled the important court position of Chief Armourer of Portugal: the 1509 Livro do Armeiro-Mor (Book of the Chief Armourer), the most important Portuguese roll of arms in existence, is thus known for having been kept by Álvaro da Costa and his descendants. Also associated with him is the Da Costa Book of Hours, 1515, now in the Morgan Library and Museum in New York.

Biography The earliest known documental evidence of Álvaro da Costa's existence has him as a chamberlain to Manuel, Duke of Beja, in 1494. When the Duke inherited the throne in 1495, Álvaro da Costa remained in the King's retinue; in 1498 he is identified as a knight of the King's household, and accompanied the King and his pregnant wife Queen Isabella when they were sworn heirs presumptive of the Crown of Castile.

At an unknown date, probably around the turn of the 16th century, Álvaro da Costa married Beatriz de Paiva. The marriage produced six children: Gil Eanes (1502), Duarte (1504), Manuel, Isabel, Ana, and Maria (1518). 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.