Portuguese ivory trade with Benin grows sharply; prices rise

In August 1517 the master of Carneiro's ship Oliveira reached Príncipe from Benin with 187 tusks which had cost 1,623 manillas — the price of ivory had risen so far that the factor doubted whether trade was profitable. The price of a slave had risen in 1517 to an average of 57 manillas, driven by competition between Sāo Tomé and Príncipe traders. In December 1514 Carneiro's factor had reported 385 tusks weighing 10,520 pounds being sold in Lisbon at 13 cruzados a hundredweight.