What's the center of the world

What those maps were actually for

The maps medieval cartographers made, called mappae mundi were not navigation tools. Nobody unrolled one to sail somewhere. They were cosmological documents, closer to a diagram of belief than a record of coastlines. Placing Jerusalem at the center was a theological statement: this is the axis of the world, the place where the human story and the divine story intersect. The map was answering the question "what matters" rather than "where is this."

That is a genuinely different project than what we call mapmaking today.

The worldview that made it logical

For a medieval European Christian, the physical world and the spiritual world were not separate categories. Sacred geography was real geography. Jerusalem was where the crucifixion happened, where the resurrection happened, where the faith located its most important events, so of course it anchored the picture of the world. East was at the top because that was the direction of paradise and the rising sun. The Garden of Eden sometimes appeared at the very top edge.

Once you understand the framework, the choice is not superstition or ignorance. It is internal consistency. They were drawing the world as they understood it to be structured at the deepest level.

What changed

Navigation changed it. When you need to get a ship from Lisbon to the coast of West Africa without dying, spiritual centrality does not help you. Portolan charts, made by sailors, for sailors, started appearing in the thirteenth and fourteenth centuries and they look strikingly modern because they were built from compass bearings and observed coastlines. Different question, different map.

The shift from Jerusalem-centered maps to compass-accurate ones is a good model for how frameworks change generally: not because people suddenly got smarter, but because the stakes of being wrong changed. When the cost of an inaccurate map was a shipwreck and a lost cargo, accuracy became the organizing principle overnight.

Both maps were rational given what each set of mapmakers was trying to do. The lesson is to always ask what question a tool or a system was built to answer, because the answer shapes everything about the design, sometimes in ways that are invisible until you need the tool to do something it was never meant for.