Roger Crowley

And he made this more scientific.

And so they'd send out ships every year as far down the coast as they could.

And when they got to the furthest point, they would leave a marker, a cross, with the arms of the King of Portugal on it so that the next ship that went down the coast could see where they'd get to and go a bit further and a bit further and a bit further.

And this is kind of almost like a scientific model of exploration.

NASA, when it's appealing for funds for exploration without an unknown outcome, has cited the Portuguese as the people who invented this strategy.

So over decades, they worked their way further down the coast, further down the coast of Africa.

And they have a very good feedback system as well.

So all the ships that came back, the captains had to produce their logbook, say where they'd been, how far south they'd got.

They had to record latitudes.

And so they're also building cartography at the same time.

This is kind of like a Renaissance exploration going on here.

And this small country, therefore, is punching very much above its weight in terms of scientific knowledge.

They acquired quite a lot of intellectual capital after the Castile expelled its Muslim population, a man called Abrao Zakutu, who was a cosmographer and who worked out a great deal about the size of the world.

So there was a kind of little intellectual hub going on in there as well.

Absolutely.

They were looking for gold, and there indeed was gold in Mali.

And they brought back some kinds of spices, but nothing very impressive.

So eventually they reach a point where they discover that there's an end to Africa in about late 1490s and comes back with this knowledge.

Very weirdly, it's not recorded in any Portuguese account because there's a climate of secrecy going on here.

They do not want interlopers on their territory.