Myth: Medieval People Thought the World Was Flat

One of the most common myths about medieval society is that people widely believed the Earth was flat, but there’s no evidence that supports this. On the contrary, by the fifth or sixth century BCE, ancient Greeks (specifically Pythagoras) had already begun investigating the planet’s true spherical nature, and by 240 BCE, Greek mathematician Eratosthenes even measured the globe’s circumference (and was pretty dead-on). In fact, the popularity of the flat Earth myth is a considerably more modern development: The myth was perpetuated in 1828 when Washington Irving, who’s known for his inventive short stories, penned The Life and Voyages of Christopher Columbus, which told a tale of the Italian explorer’s mission to prove that the Earth has curves.