He was directing construction work on the Alcochete harbour when he was struck down by malaria, which left him temporarily incapacitated and took him to a retreat in Switzerland for a full recovery. Around this time, he began his more in-depth studies of the History of Portugal and, in particular, the History of the Discoveries. He was particularly interested in the scientific foundations of Portuguese navigations, focussing on dispelling the legend created by Alexander Humboldt a few decades earlier that Portuguese nautical knowledge in the 1500s had German origins and had arrived in Lisbon with the German Martin Behain, who had brought Regiomontano ’ s knowledge and books with him.

Joaquim Bensaúde was thus following the trail laid down in the 1940s by the Viscount of Santarém, when he published his Recherches sur la priorité de la découverte des Pays sur la côte Occidental d’Afrique [Research on the priority of the discovery of countries on the west coast of Africa] . However, the centrepiece of his research was the history of nautical science itself, taking as his starting point a 15 th -century Portuguese nautical text that he had found in the Munich Municipal Library. In truth – as he himself tells us – his studies began shortly after 1890 when he came into contact with the studies of Meyer Kayserling and, above all, Moritz Steinschneider ( Die Hebräischen [The Hebrews] , 1893), which alerted him to the work of Abraão Zacuto and other Jewish astronomers from the Iberian Peninsula. And by associating these studies with the document he found in Munich, he developed the idea that Portuguese nautical knowledge from the period of the Expansion had a different origin from that announced by Humbold, allowing him to categorically challenge his theory with the publication of the study L’Astronomie Nautique au Portugal à l’Époque des grandes Découvertes [Nautical Astronomy in Portugal at the time of the Great Discoveries] in 1912 .

1 | 2 | 3 | 4 | 5 | (Pdf)