For Europeans in the 1450s, the Western Ocean (or the Atlantic as we now call it) was a frightening place. Unlike the cozy, well-mapped Mediterranean which was surrounded by three continents, the Western Ocean was unbounded, poorly understood, and filled with dangers.
The dangers were not the threat of sea monsters or falling off the edge of the world. Medieval sailors and geographers understood that the earth was spherical. (The idea that they thought it was flat is a fantasy conjured up by Washington Irving in his 1828 biography of Christopher Columbus.)
Rather, the real threat was the ocean itself. Expeditions that followed the West African coast had revealed strong winds and currents that made travel south (with the current) easy, but return extremely difficult, especially with vessels that could not tack close to the wind. By the 1430s, Europeans had even identified a spot on the West African coast, Cape Bojador, as the point of no return.
And yet Europeans, led by the Portuguese, continued to push further south despite this risk. They developed trade factories off the west coast of Africa which exchanged Europeans goods — horses, wool, iron — for gold, ivory, and slaves. And ultimately they followed the African coast around the Cape of Good Hope and into the Indian Ocean, reaching the Indies — the holy grail of luxury items — in 1498.
All of this makes European exploration seem logical and methodical, driven by the promise of riches. Yet Europeans were interested in more than slaves and spices. Africa attracted Europe’s attention because it was considered the most likely location of Prester John, legendary Christian king and potential ally in the fight against the Muslims who occupied the Holy Land.
Historians have long placed Prester John within the category of myth, and in so far as myths describe “traditional stories, usually concerning heroes or events, with or without a determinable basis of fact” I suppose Prester John qualifies.
But “myth” has subtler, darker meanings. The world is filled with traditional stories that have a tenuous relationship to observable facts: the Gospels, the Koran, and the Torah are filled with them. Yet we describe these stories as “beliefs” out of faith or respect. We usually reserve the word “myth,” however, for those stories — unicorns, leprechauns, a living Elvis — that we dismiss as untrue.
The point here is not to say that Prester John was real, but to say that in characterizing him as a mythic figure, historians have tended to discount his serious influence on European exploration and discovery.
This is a central argument of historian Michael Brooks in his excellent thesis, Prester John: A Reexamination and Compendium of the Mythical Figure Who Helped Spark European Expansion. Brooks shows that, while it might be clear in hindsight that Prester John was more fable than reality, it was not clear to Europeans in the 15th and 16th centuries, all of whom could point to multiple accounts of the Christian king from different, trustworthy sources. The Travels of Sir John Mandeville, one of the most popular books in late medieval Europe, even offers a first-hand account of Prester John’s palace:
He dwelleth commonly in the city of Susa. And there is his principal palace, that is so rich and so noble, that no man will trow it by estimation, but he had seen it. And above the chief tower of the palace be two round pommels of gold, and in everych of them be two carbuncles great and large, that shine full bright upon the night. And the principal gates of his palace be of precious stone that men clepe sardonyx, and the border and the bars be of ivory. [Mandeville quoted in Brooks, 87]
On the basis of these multiple, mutually supportive documents, Dom Henrique (Henry the Navigator) charged his explorers to bring back intelligence about the Indies and of the land of Prester John. This was not merely an addendum to their orders for geographical discovery. Argues Brooks:
Without the lure of making political connections with the supposed co-religionist Prester John in the struggle against the Islamic world, the European history of overseas expansions would likely have taken a different course .
This serious, sustained interest in Prester John helps explain the longevity of the legend well into the seventeenth century. I could not help seeing many similarities in Brooks’ account of Prester John with other stories of exploration. The one I have written the most about, the theory of the open polar sea, has also been discounted by historians as “myth” even though it was taken very seriously by scientists, explorers, and geographers in the nineteenth century, shaping the missions of numerous explorers.
Brooks’ thesis is available in pdf here.
He also posts a number of articles and reviews on history and exploration on his blog, historymike.