João Baptista Lavanha

[2] At the time of the Portuguese succession crisis of 1580, Philip II of Spain sent troops under the command of Fernando Álvarez de Toledo, 3rd Duke of Alba to subdue Portugal.

Lavanha was appointed on 4 November 1586 by the King to the newly created post of Master Engineer of the Kingdom of Portugal, holding teaching duties at the Academy of Mathematics and Architecture in Madrid.

Faced with the illness of Tomás de Orta, he began to serve as the Royal Chief Cosmographer of the Kingdom from 13 February 1591, a position for which he was officially appointed in 1596.

[3] Lavanha was the author of works as diverse as a translation of Euclid, the "Nautical Regiment" (1595), where he presents rules for the determination of latitude and tables of declination of the Sun, the "wreck of the Santo Alberto, captained by Julião de Faria Cerveira, off 'Penedo das Fontes' (Kwaaihoek, South Africa) in 1593" (1597), the "First Book of Naval Architecture" (c. 1608), currently in the Library of the Royal Academy of History of Madrid, the "Compendium of Affairs of Spain and Description of the Universe", and unpublished as the "Art of Navigating", the "Treaty of Gnomonics" and finally the "Treaty of the Astrolabe", a copy of which is in the Library of the Astronomical Observatory of Coimbra.

At the request of his heirs, he edited and compiled João de Barros' scattered manuscript into the fourth volume of the "Decades of Asia" and published it in Madrid in 1615.