The Shipwreck of Bom Jesus, AD 1533: Fugger Copper in Namibia

Abstract

In AD 1533, the Portuguese trade vessel Bom Jesus sunk off the coast of southern Namibia, near the modern town of Oranjemund. Coming from Lisbon on its way to western India, it contained a multifold load of naval equipment and commodities for trade and exchange. Amongst the excavated materials recovered from the presumed shipwreck of the Bom Jesus, of paramount importance are 1845 copper ingots, showing the trademark of the Fugger company from the Freie Reichsstadt of Augsburg, Germany. Historical accounts testify to massive copper and silver production of the Fugger-Thurzo company in the area of Neusohl in the Slovak Ore Mountains. Geochemical analyses of 60 copper ingots from the wreck show an extraordinarily homogeneous composition with appreciable concentrations of lead, silver, antimony, nickel, and arsenic indicating the smelting of fahlores. Lead was found to be added deliberately to the copper to extract silver by the Liquation Process. This technological innovation is one of the numerous hallmarks of the Renaissance period and the “Age of Discovery”. Lead isotope abundance ratios point to an origin from lead deposits in Cracow-Silesia. The ore districts of Neusohl and Cracow-Silesia were intensively connected to mining and metal production during the postmedieval period. This study forcefully shows the advantage of combined historical and natural science studies.