The flat earth myth is one of the most durable anti-Catholic stories ever told. Monks chained Bibles, feared the edge of the world, and crushed anyone who said the earth was round. Then you read the monks. In the early 8th century, the Venerable Bede wrote De Ratione Temporum, a manual for computing the date of Easter. In it he describes the earth plainly as a sphere, explains the zones of the heavens, and works through how sunlight strikes different latitudes across the year. This was not a secret whispered against Church teaching. It was standard operating procedure. Bede was teaching it to monks so they could run the liturgical calendar. And he was not eccentric. Medieval scholars inherited the spherical earth from Greek astronomy and never lost it. The standard university text on cosmology, used for centuries, presented the round earth as settled fact. So the question is not whether a few medievals knew the earth was round. The question is who invented the flat earth story about them, and why the invention stuck so well. The 19th century popularized it as a weapon: religion suppresses knowledge, science liberates it. It survives not because anyone documented medieval flat-earthism, but because the narrative was too useful to fact-check. A monk in a Northumbrian monastery, hand-copying computus tables by candlelight, was doing more rigorous astronomy than the people who mock him today have ever done. Which is easier to believe: that an entire civilization forgot the shape of the planet for a thousand years, or that someone told you a story about it that you never checked?