The Bom Jesus and the Skeleton Coast

A 1533 treasure ship found in a drained diamond-field lagoon in 2008

The Bom Jesus was a Portuguese nau, an Indiaman, that sailed from Lisbon on Friday, 7 March 1533, probably bound round the tip of Africa for western India, and was never heard from again. For 475 years she was one more ship lost on the turn of the Cape of Good Hope. Then, on 1 April 2008, Kaapanda Shadika, a De Beers employee working an inshore diamond pit near Oranjemund on Namibia's southern coast, turned up copper ingots and pieces of elephant ivory.

The diamond company's archaeologist, Dieter Noli, saw that the wreck was old and called in the maritime archaeologist Bruno Werz. Behind sand walls built to hold back the sea, the remains lay in three large sections along the shore, much of it sealed in a metre-thick crust of orange concretion that had preserved the hull and made recovery slow. Mining stopped, and when the find went public a rare Portuguese cruzado coin brought Portugal, Spain and Texas A&M University to help, under an agreement drawn up at Oranjemund.

The cargo ran to more than 40 tons: cannons, firearms, swords, navigational instruments, lead and tin, 1,845 copper ingots weighing some 16 to 17 tons, more than 2,000 gold and silver coins from several maritime powers, and 105 elephant tusks weighing close to 2 tons. A trident mark on the copper traced it to Anton Fugger's trading house of Augsburg, and geochemistry to the Fugger-Thurzo mines in the Slovak Ore Mountains. DNA and isotope work on the tusks showed West African forest elephants, mostly from savanna habitats, from around 17 different herds, and genetically more diverse than modern forest elephants. Very few human bones were found, which suggests most of the crew either survived or died at sea. The ship had probably been driven too close to shore in a violent storm, struck a rock and capsized, spilling the captain's coin chest before the hull broke up along the beach.

Because the wreck lay inside a tightly guarded diamond area, nothing was looted, and every piece could be recovered and catalogued, the oldest and most valuable shipwreck ever found off the western coast of sub-Saharan Africa. Archaeologists read it as a window on the first maritime trade linking Europe, Africa and Asia, fed by overland networks from the Slovak mountains to the West African forest. The site lies inside a secure diamond mining area, so the place to meet the Bom Jesus is through her cargo.