There is a piece of 'common knowledge' about the Middle Ages we have heard repeated over and over again: that medieval people thought the earth was flat. In addition, there's a second claim we've heard a few times: that Columbus faced opposition to his attempt to find a western route to Asia because people thought the earth was flat and he'd fall off. Widespread 'facts' with one very, very big problem: Columbus, and many if not most medieval people, knew the earth was round. As did many ancient Europeans, and those since.

The Truth

By the Middle Ages, there was a widespread belief among the educated that the Earth was a globe. Columbus did face opposition on his voyage, but not from people who thought he’d drop off the edge of the world. Instead, people believed he’d predicted too small a globe and would run out of supplies before he made it around to Asia. It was not edges of the world people feared, but the world being too big and round for them to cross with the technology available.

Understanding the Earth as a Globe

People in Europe probably did believe that the earth was flat at one stage, but that was in the very early ancient period, possible before the 4th century BCE, the very early phases of European civilization. It was around this date that Greek thinkers began to not only realize the earth was a globe but calculated the precise dimensions of our planet.

There was much discussion about which competing size theory was correct, and whether people lived on the other side of the world. The transition from the ancient world to the medieval one is often blamed for a loss of knowledge, a “move backward”, but the belief that the world was a globe is evident in writers from across the period. The few examples of those who doubted it have been stressed instead of the thousands of examples of those who didn’t.

Why the flat Earth myth?

The idea that medieval people thought the earth was flat appears to have spread in the late nineteenth century as a stick with which to beat the medieval Christian church, which is often blamed for restricting intellectual growth in the period. The myth also taps into people’s ideas of “progress” and of the medieval era as a period of savagery without much thought.

Professor Jeffrey Russell argues that the Columbus myth originated in a history of Columbus from 1828 by Washington Irving, which claimed that theologians and experts of the period opposed funding the voyages because the earth was flat. This is now known to be false, but anti-Christian thinkers seized upon it. Indeed, in a presentation summarizing his book ‘Inventing the Flat Earth: Columbus and Modern Historians,’ Russell states:

No one before the 1830s believed that medieval people thought that the Earth was flat.