About WhoRuled

WhoRuled is a free interactive map of who ruled where. Move the year slider, click a state, and see its rulers, government and sources.

Where the data comes from

Borders: historical-basemaps by Andre Ourednik, GPL-3.0. Historical borders are approximate; the source dataset has snapshots only for certain years, so the map shows the nearest one you select. Its last snapshot is 2010.
Present-day borders (2026): Natural Earth 1:50m countries, public domain. Made with Natural Earth.
Rulers and offices: curated entries (each with a source link and quoted words) and an import from Wikipedia's "List of state leaders" pages, used under CC BY-SA 4.0. State identities are Wikidata items (CC0).
Hierarchy: the overlord and subjects shown for a state come from the border dataset and are not curated.

How reliable is it?

Every ruler, office, army figure and event links to its source. Army sizes are shown only with a citation and a confidence level.

Report a mistake

Open an issue on GitHub with the state, year and a source.

Affiliate links

Some state pages link to books on Amazon. As an Amazon Associate I earn from qualifying purchases. It does not change the price you pay.

Open source

Code is MIT-licensed, curated facts are CC0 (imported Wikipedia rows stay CC BY-SA), the historical border geometry is GPL-3.0, and the present-day (2026) geometry from Natural Earth is public domain. See LICENSING.md.