Medieval People Did Not Think the Earth Was Flat
Where the Myth Really Came From

The story goes that people in the Middle Ages thought the Earth was flat, and that Columbus sailed west to prove them wrong. The medieval writers themselves say otherwise. Below is what they wrote, who did disagree, and how the myth was put together centuries later.

What medieval scholars wrote

Myth The educated medieval world did not teach a flat Earth. Three examples, from the 8th and 13th centuries:

• Bede, the English monk, explained around 723 or 725 that the Earth “is, in fact, a sphere set in the middle of the whole universe.” He drew the distinction the myth forgets: “It is not merely circular like a shield [or] spread out like a wheel, but resembles more a ball, being equally round in all directions” (The Reckoning of Time, in Faith Wallis’s translation, as quoted by the British Library).
• Sacrobosco’s De sphaera, a 13th-century astronomy treatise, has a section headed “The Earth a Sphere”. It argues: “That the earth, too, is round is shown thus.” One of its proofs is that the same eclipse of the Moon is seen at different hours in different places. It even explains why the Earth looks flat: “But it seems flat to human sight because it is so extensive.” (Translation by Lynn Thorndike, 1949.)
• Thomas Aquinas, needing an example of something two sciences can both prove, reached for this one: “the earth, for instance, is round” (Summa Theologiae I, question 1, article 1). He offered it as a plain example, without arguing for it.

Alison Hudson, writing on the British Library’s medieval manuscripts blog, sums up the record: “It is actually rare to find groups in the classical, Late Antique and medieval eras who believed in the flat Earth.”

The real exceptions

A few early Christian writers did reject a round Earth, and they should not be explained away.

• Lactantius mocked the idea: “Or is there any one so senseless as to believe that there are men whose footsteps are higher than their heads?” (Divine Institutes III.24.)
• Cosmas Indicopleustes, a 6th-century Egyptian monk, most probably from Alexandria, described a flat, oblong world modelled on the Tabernacle: “The Deity accordingly having founded the earth, which is oblong, upon its own stability”. His editor dates the work to around 535–547. His influence was limited: a historian quoted by that editor says it “is only slightly, and occasionally, traceable.”

How many such writers were there? The historian Jeffrey Burton Russell counts “at least two and at most five” early Christian fathers, and adds that “tens of thousands of Christian theologians, poets, artists, and scientists took the spherical view”. Not every early writer took a side: Basil of Caesarea listed the shapes proposed — “spherical or cylindrical”, a disc, or “a winnowing basket” — and declined to choose (Hexaemeron IX.1).

The antipodes: a different question

Some writers who accepted a round Earth still doubted that people lived on the far side of it. Saint Augustine, in The City of God (XVI.9), rejects “the fable that there are Antipodes, that is to say, men on the opposite side of the earth”, while granting that even if it be “supposed or scientifically demonstrated that the world is of a round and spherical form”, it does not follow that anyone lives on the other side. Bede too, the British Library notes, “denied that anyone lived in the southern hemisphere at all”.

That distinction matters, because the myth was built partly by blurring it.

How the myth was built

Washington Irving, 1828. Irving’s biography of Columbus dramatised a hearing at Salamanca in which, he wrote, “To his simplest proposition, the spherical form of the earth, were opposed figurative texts of scripture.” Even Irving’s own scene is more mixed than the legend: he adds that “Others, more versed in science, admitted the globular form of the earth”, and that among their objections was that the circumference “must be so great as to require at least three years to the voyage”.

Letronne, 1834. The French scholar Antoine-Jean Letronne opened by describing a time “pas encore bien loin de nous” — not yet far from us — when a map-maker “devait poser en principe que la terre était une surface plane” — had to take it as a principle that the Earth was a flat surface (our translation). He conceded that some theologians let the Earth be round, on condition that there were no antipodes. He listed “Saint Augustin, Lactance, saint Basile, saint Ambroise” among those who rejected a round Earth. Putting Augustine on that list turns doubt about the antipodes into belief in a flat Earth.

Draper, 1870s. John William Draper’s History of the Conflict between Religion and Science said the philosophy of the Church Fathers held of the Earth “that it is a flat surface, over which the sky is spread like a dome”, and that “the question of the shape of the earth was finally settled by three sailors”.

White, 1896. Andrew Dickson White’s A History of the Warfare of Science with Theology in Christendom concedes that thinkers such as Aquinas and Dante “felt obliged to accept the doctrine of the earth’s sphericity.” But it framed the history as a war, claiming that “the great majority of the early fathers of the Church, and especially Lactantius, had sought to crush it” — a claim the count above does not support, and White himself writes a few lines on that Ambrose and Augustine “had tolerated it”.

Russell’s summary: “No one before the 1830s believed that medieval people thought that the earth was flat.” He names Irving (1828) and Letronne as the two who established the idea, which by the 1860s was being “served up in schools and in schoolbooks as the solemn truth”. The charge against a few Church Fathers is older, though: in the 17th century Robert Burton’s The Anatomy of Melancholy already said Augustine, Basil and Lactantius held the Earth “round as a trencher” — a flat plate — rather than a ball.

What the Columbus argument was about

Myth Columbus did not have to persuade experts that the Earth was round. As the historian of science Darin Hayton puts it, “Columbus and all his detractors knew that the earth was round.”

Even Irving, whose Salamanca scene helped start the legend, wrote that the success of Columbus’s undertaking “depended upon two happy errors, the imaginary extent of Asia to the east;” and the supposed smallness of the Earth. Columbus thought the world was small enough to reach Asia by sailing west. The Americas lay in between.

What we cannot know

Unverified Almost every surviving source comes from educated people: monks, scholars, map-makers. Round-Earth ideas did reach books outside the schools — Mandeville’s Travels says “that the land and the sea be of round shape and form” — but no record measures what most ordinary, unlettered people believed about the shape of the Earth, if they thought about it at all. What can be said is that the scholarly record is overwhelmingly for a sphere, and the rest is largely unrecorded.

Our reading

The flat-Earth Middle Ages is largely a 19th-century creation, though the charge against a few Church Fathers is older, and it says more about the 19th century than the medieval one: it was useful to writers who wanted a story of science defeating religion. The history has more texture — a few genuine flat-Earth writers, a real and separate debate about the antipodes, and a Columbus who was wrong about the number that mattered.

Sources

• Bede, The Reckoning of Time, trans. Faith Wallis (Liverpool University Press, 1999), as quoted in Alison Hudson, “‘The Earth is, in fact, round’”, British Library Medieval Manuscripts blog (24 May 2018).
• The Sphere of Sacrobosco, trans. Lynn Thorndike (1949).
• Thomas Aquinas, Summa Theologiae I, q.1, a.1, trans. Fathers of the English Dominican Province (1920).
• Augustine, The City of God XVI.9, trans. Marcus Dods.
• Lactantius, Divine Institutes III.24, trans. William Fletcher.
• Cosmas Indicopleustes, The Christian Topography, trans. and intro. J. W. McCrindle (Hakluyt Society, 1897).
• The Travels of Sir John Mandeville (Macmillan, 1900).
• Washington Irving, A History of the Life and Voyages of Christopher Columbus, vol. I (John Murray, 1828).
• A.-J. Letronne, “Des opinions cosmographiques des Pères de l’Église”, Revue des Deux Mondes (1834).
• John William Draper, History of the Conflict between Religion and Science (1870s).
• Andrew Dickson White, A History of the Warfare of Science with Theology in Christendom (1896).
• Darin Hayton, “Washington Irving’s Columbus and the Flat Earth” (2 December 2014).
• Basil of Caesarea, Hexaemeron IX.1, trans. Blomfield Jackson.
• Robert Burton, The Anatomy of Melancholy.
• Jeffrey Burton Russell, “The Myth of the Flat Earth”, American Scientific Affiliation (1997), summarising Inventing the Flat Earth (1991).

Checked September 2026.

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