Duarte d`Armas was born in Lisbon in 1465, but it is unknown the date on which he died.
He was squire of the Royal House and a portuguese drawer.
With great ability to draw, he was delegated by D. Manuel I (1495-1521) to check the condition of the fortifications of the frontier of Portugal with the kingdom of Castile, what he accomplished with panoramic and plants.
From this work resulted the book of Strengths, manuscript between 1509 and 1510.
The book presents drawings of 56 frontier castles of the kingdom of Portugal, that were visited by the author, accompanied by a servant.
This route proposes to recreat part of this trip and visit the castles and historic area, starting in Beira Alta, Castels of Vila Maior, Sabugal, Castelo Bom, Castelo Mendo, Almeida and Castelo Rodrigo, proceed by Douro, Castles of Freixo de Espada à Cinta, Mogadouro, Penas Róias and Miranda do Douro and finishing in Trás-os-Montes, Castles of Outeiro, Bragança, Vinhais, Monforte de Rio Livre and Chaves.