Was Christopher Columbus acting on any tips from prior travellers?

Is there any credible evidence that Christopher Columbus was tipped off to the possibility of reaching “Asia” via the Atlantic from someone who had been there, e.g. Portugese fishermen or a source familiar with them? Or is that all hokum and would his initiative have been entirely based on calculations of the distance needed to make the journey?

Others will be along to say more, but this is a recent podcast on the subject that looks to be well researched.


The short answer is that CC thought he had found old documents that gave a smaller size for the earth. They were wrong. He was incredibly lucky.

But it might well be that he only believed those documents because he knew of others who had sailed west and reached land.

There have been (not proven) speculations that Columbus had heard about land in the West from Basque fishermen and/or Scandinavian sources, AFAIK a former voyage by Columbus to Scandinavia is documented.

And of course Leif Eriksen went to Newfoundland about half a millennium before CC’s journey.

This is a huge and long-running debate.

First, Columbus took the view of a different old philosopher. One ancient Greek calculated the diameter of the earth and got remarkably close, using the angle of the sun at noon and the distance south between two cities (in Greece and Egypt). He got about 8,000 miles. A different ancient scientist came up with about 5200 miles. Of course, in those days the units were pretty ambiguous- Columbus used a different definition of the units involved and said it was 4500 miles. That would make the diameter of Earth about 13,500 miles. He then took Marco Polo’s diaries and estimated the distance Polo travelled to China going east was 10,000 miles. (That number was a bit high, too…) So there should be China and the Indies (spice islands of Indonesia) about 3,000 miles or so west across the Atlantic.

It was one of life’s happy coincidences that he ran into the Americas. The intelligentsia of Europe believed the original Greek number of 8,000 miles in diameter, making China over 12,000 miles west - way too far for the ships of the day. This is why he had a hard time selling his idea to the courts of Europe - until Portugal was monopolizing the route sailing around Africa, so rival Spain decided “what the hell! Worth a try!”

There have always been suggestions Columbus knew from Basque fisherman about lands northwest (Newfoundland) where the Grand Banks absolutely teemed with cod. There’s evidence the Basques were fishing there about the same time as Columbus’ voyage. There’s also the story that the Bristol fishermen knew this place - some were charged with importing processed (dried and salted) cod from elsewhere without paying taxes, then the case was dropped. Speculation is by the 1480’s they too knew of the Grand Banks and would put ashore in Newfoundland or Labrador to dry and salt their cod for the trip home. They just didn’t want to talk about a lucrative secret fishing hole in open court. John Cabot didn’t waste any time discovering Newfoundland in 1497 on a commission from England after Columbus’ discovery was public.

There’s also speculation Columbus had sailed with a ship to Ireland and heard of these lands to the west. Or heard Viking stories of Greenland (now lost) and Vineland.

Short answer is, we’ll probably never know for sure why Columbus had an obsession with the short route to China.

Best evidence is the case against the Bristol fishermen in the 1480’s that was dropped without explanation - which would indicate they knew about Newfoundland. But whether Columbus heard about this, or from the the Basques - who knows?

That in itself proves nothing. They might have bribed the judge, or some powerful lord might have intervened. The justice system was rife with abuse at that time.

If the Basques knew the land was there, why did they tell no one? If they told no one to keep it a secret - why blab to Columbus? If they told Columbus about it, why did he head for the Caribbean, and not Canada?

This theory is way more convoluted than it needs to be, as opposed to: “I know that India is thataway, and it’s probably not as far as everyone says it is.”

I doubt anyone told Columbus they had reached ‘India’ or anywhere else specific, and the believed circumference of the earth probably wasn’t a factor. Columbus probably believed stories of sailors who said they had been to lands in the east, which may have included stories that originated with the Norse, or tales of finding storm swept vegetation in the Atlantic, perhaps even sailors who had reached the Americas or thought they did, and stories that were total fiction or just entirely confused about which way was east… Columbus like all the explorers of the time followed a hunch or just believed if he kept looking he’d find something. We hear about the explorers who found something and returned, any number of them found nothing, and many of those never returned. Columbus was just lucky.

ETA: The above based on the lack of evidence to the contrary. Possibly some day some writing will turn up with more details, but then the controversy just changes direction because of the difficulty in authenticating such a thing.

Well, happy for him, for the natives of the lands he encountered… not so much.

md-2000 already mentioned it, but I think Marco Polo’s account (ghostwritten by a prison mate with whom Polo shared a cell after his return) of his travels to and in China (the “Book of Marvels”) deserves special attention. It is well documented that Columbus had read it; his possessions include a hand-annotated copy of it. It was this book that gave Europeans from the 13th century onwards the idea of the existence of powerful and wealthy lands in Central and East Asia that could be lucrative to trade with. Sure, that book didn’t help much in figuring out how to reach East Asia travelling westwards, but it was this work that made it a worthwhile endeavour to even try.

Maybe they ordinarily told no one, because they wanted to keep a monopoly on those profitable fishing grounds, but Columbus managed to get a few of them drunk enough to blab. Maybe a few others got them drunk enough, too, but didn’t believe them. It’s not all that far-fetched.

As to why he headed south, that’s the step at which we introduce his flawed assumptions about the size of the Earth. The reasoning on Columbus’ part would go something like this:

“Those fishermen reached land to the West.
If that land was Asia, then the Earth must be much smaller than conventional wisdom thinks.
But the lands they reached were northerly, and not particularly rich.
The rich lands we know of in Asia are all further south.
If they reached northern Asia by sailing northwest, then I could reach southern Asia by sailing southwest.”

It’s a lot more reasonable than a chain of inference that starts with “The Earth must be much smaller than conventional wisdom thinks, because I want it to be”.

He actually took a southern route because the prevailing winds and currents are to the westward there. Farther north he would have been going against the winds.

I don’t think you even need to posit explicit secrecy broken by drunkenness. Information simply didn’t travel as far in those days and knowledge of lands out west could have persisted a long time in local folklore without it catching the attention of the kind of people who draw maps and claim lands for monarchs.

I’ve heard it suggested that there has been perpetual low-level contact between Europe and the Americas since at least the viking era, and that Columbus was just the first expedition that had a press conference afterwards.

Europeans were well aware of China long before Marco Polo.

Trade between Europe and China had been going on via the Silk Road since Roman times, and continued with few interruptions during the medieval period.

From the wiki on Europeans in Medieval China:

Given textual and archaeological evidence, it is thought that thousands of Europeans lived in Imperial China during the period of Mongol rule.

These were people from countries traditionally belonging to the lands of Christendom during the High to Late Middle Ages who visited, traded, performed Christian missionary work, or lived in China. This occurred primarily during the second half of the 13th century and the first half of the 14th century, coinciding with the rule of the Mongol Empire, which ruled over a large part of Eurasia and connected Europe with their Chinese dominion of the Yuan dynasty (1271–1368).

Whereas the Byzantine Empire centered in Greece and Anatolia maintained rare incidences of correspondence with the Tang, Song and Ming dynasties of China, the Roman papacy sent several missionaries and embassies to the early Mongol Empire as well as to Khanbaliq (modern Beijing), the capital of the Mongol-led Yuan Dynasty.

With Popes sending ambassadors and missionaries to Beijing during the Yan Dynasty (1279–1368), China was not a great mystery to educated people in medieval Europe.

Both cities (Alexandria and Syene) were in Egypt. They had reasonably accurate measurements for land distances, not so much for sea distances.

It was bound to happen.

Yeah, but perhaps without Columbus it would’ve happened 100 year later, 4 generations without invasions are happier than 300 or so europeans not sinking.

Then why no disease resistance in the Native Americans?

If the Basques, or anyone else, had traveled from southern Europe to the northwest Atlantic they may have found the Gulf Stream and started their journey on the same course Columbus took. He was trying to follow western currents. I do think it’s unlikely anyone had crossed the Atlantic that way, but the stories might have existed.