I often hear people refer to a time in history (usually in the context of European history) when it was common knowledge that the earth was flat but I have also heard various people deny that there was ever a time when a truly significant portion of the population believed this. They acknowledge that maybe some significant church figures believed this claim but outside of that, not many people actually thought that. I’m interested to know what common knowledge on this subject would’ve actually been in that time period rather than what I’ve heard people say they believed without providing any credible sources or evidence. Thanks and links to any sources on this would be greatly appreciated!
No, common people in medieval Europe did not believe the earth was flat. I've written about this from several angles before:
In which medieval people heard sermons that referred to the earth as spherical
And in which Columbus really screwed up his math
To quote from that first one a bit:
his is a tricky question to answer, because by definition if someone leaves behind a written record where they're casually referring to earth as a sphere, they are educated (as in, they know how to write). But we can be pretty sure that a spherical Earth was commonly known from a couple of sources:
- the Elucidarium written by Honorius Augustodunensis around 1120 refers to the Earth as a sphere. The Elucidarium was a manual for the instruction of clergy, and was translated into multiple languages. (I'm copy-pasting these from Wiki because I don't feel like retyping them: "Middle English, Old French, Middle High German, Old Russian, Middle Dutch, Old Norse, Icelandic, Spanish, and several Italian dialects.") The lesser clergy were those most likely to preach and minister directly to commoners, of course.
- We have surviving sermons from Bertold von Regensburg, a German cleric, that refer to the Earth as spherical (not in the sense that he's revealing a great mystery of the Earth, but as an analogy that his hearers would be familiar with). His sermons were in the vernacular German dialect of his time period (mid-13th century), so there's evidence that he was using that metaphor in the local language that the local people would be aware of.
The question that early explorers faced, of course, wasn't so much whether the world was a sphere as it was how big it was -- Columbus in particular overestimated the size of Eurasia and underestimated the Earth's circumference.