Scientists have discovered that some of the Benin bronzes were made with brass mined thousands of miles away in the German Rhineland.
The Edo people in the Kingdom of Benin, modern Nigeria, created their extraordinary sculptures with melted down brass manilla bracelets, the grim currency of the transatlantic slave trade between the 16th and 19th centuries.
While rarely found in archaeological excavations on land, they have been retrieved in substantial numbers from the wrecks of vessels that had been transporting them.
In carrying out the largest study of these bracelets, a team of German researchers compared their metal with metallic ores and mines across Europe before tracing them to the Rhineland in western Germany.
Long been known in fact. Which, of course, means the Benin Bronzes should be sent to San Francisco in reparations.