BY THE 1450S, ACCORDING to Henry’s chronicler Cadamosto, the slave-trading station built at Henry’s behest at Arguim, an island off modern-day Mauritania, was supplying eight hundred to a thousand slaves a year to a burgeoning Portuguese market in Africans. As ridiculous as a comparison to Alexander now sounds, in terms of human capital, this amounted to an immense bounty for those times, and ships began departing Portugal for Africa in large convoys to partake in the traffic.
