About
About the Data
World History Atlas aims to show the world’s borders honestly, clearly, and fairly. Here’s exactly where the data comes from and how it’s used.
Historical Border Data
The primary source for historical borders is aourednik/historical-basemaps by André Ourednik, an open-licensed collection of GeoJSON snapshots covering world history from 3000 BCE to the present.
Supplementary coverage comes from OpenHistoricalMap, a collaborative project that attaches date ranges to geographic features.
Precision levels
- 1 — Approximate: border shown with a blurred/soft edge; location is uncertain.
- 2 — Estimated: reasonable scholarly consensus, but not formally documented.
- 3 — Defined: historically or legally documented border; rendered with a crisp line.
Important:the slider snaps to years where sourced data actually exists. No borders are interpolated between data points. A steady map between ticks reflects our data’s resolution, not history standing still.
Known data limitations
- 53 snapshots total — coverage jumps by centuries in ancient history (e.g. nothing between 1000–1100 CE). Each arrow key press jumps to the next real data year.
- Placeholder names — sparsely documented regions (parts of Africa, the Americas, Central Asia before 1000 CE) may be labeled with modern country or region names rather than the historical polity. This is a known issue in the source dataset, not an error in our rendering.
- Simplified boundaries — some pre-modern borders are scholarly estimates drawn at a continental scale. Treat them as approximate extents, not surveyed lines.
- Contributions and corrections welcome at the upstream project.
What We Don’t Use
Euratlas maps are used only for visual verification. Their vectors are commercially licensed and are never ingested, traced, or incorporated into this site.
Text Content
Summaries are fetched from the Wikipedia REST API and are licensed under CC BY-SA 4.0. Entity data (identifiers, Wikipedia title linkages) comes from Wikidata (CC0 / public domain).
Images
Representative images are pulled from Wikimedia Commons via the Wikidata P18 (image) property. Each image is displayed with its license and author credit exactly as provided by Wikimedia Commons. No AI-generated historical images are used.
Preferred image sources include public domain and CC0 collections such as the Smithsonian Open Access, The Metropolitan Museum of Art, the Rijksmuseum, and the Cleveland Museum of Art — wherever those are associated with the Wikidata entity.
Methodology
- No fake interpolation. The map only shows states that are supported by source data. Between known snapshot years, the display holds steady at the most recent sourced state.
- Honest precision. Border fuzziness is rendered differently by precision level — approximate borders blur, defined borders are crisp.
- Concrete and fair. Interpretations are attributed; the site does not editorialize.
- Geometry pipeline. Borders are simplified using mapshaper with topology-preserving Visvalingam–Whyatt simplification, so shared borders never split into gaps or slivers.
Contributing & Corrections
If you spot a border error, please consider contributing a fix upstream to aourednik/historical-basemaps per the project’s contributing guidelines.