About this atlas

World Empires maps real historical borders from 3000 BC to 1945. Every polygon on the map comes from the Seshat Cliopatria dataset, a peer-reviewed geopolitical record assembled by historians and archaeologists. The year slider lets you step through 48 snapshot dates, from 3000 BC to AD 2026, and see which polities controlled which territory at each point.

Each polity entry includes the dates it was active, the region or regions it occupied, and, where the data support it, peak territorial extent in km², peak population, and a sourced chronology of rulers and key events.

Border precision

Pre-modern borders were rarely fixed lines. The polygons here represent the approximate maximum extent of political control at each snapshot year, not a surveyed boundary. For periods before the 16th century, treat them as informed historical estimates, not precise demarcations. Each polity detail page notes the sources and any material uncertainty.

Borders are drawn from the Seshat Cliopatria shapefiles, simplified with Mapshaper for web delivery. The simplification preserves coastlines and major river boundaries; minor internal features may be smoothed.

Snapshot years

The map shows borders at 45 fixed snapshot dates rather than every year. The slider snaps to these dates only. When a polity was active across several snapshots, you will see it at each one; when the snapshot falls between two phases of a polity, the nearest in-range snapshot is used.

The earliest snapshot is 3000 BC and the latest is 1945. Coverage is denser from 1 BC onwards. Earlier periods have snapshots every 100–500 years; later periods have them every 5–35 years. The slider shows the actual snapshot year in the thumb label so you always know which date is displayed.

Overlapping polities

Overlapping polities are expected, especially before 1648 when the modern international order of sovereign, mutually exclusive territories began to consolidate. A tributary state may sit inside a suzerain's territory; a city state may overlap a regional empire that claims nominal authority over it.

On the map, fills are semi-transparent so overlaps are visible. Tapping or clicking a location where more than one polity is present shows a chooser listing all of them, so neither is silently dismissed. Outlines are fully opaque at 1.5–2 px so boundaries remain legible even at low zoom.

Polities without map data

Some polities in the catalogue have no matching polygon in the Seshat dataset. Where a capital is recorded, the map shows a point marker at that location with a “Boundary data not available for this period” note. The polity still appears in the browse index with full detail.

How years are displayed

Years use UK convention: BC suffix, AD prefix. “146 BC”, “AD 117”. Internally, the atlas uses astronomical year numbering (1 BC = year 0, 2 BC = year −1) so that arithmetic across the BC/AD boundary works without gaps. The display always converts back to the familiar BC/AD form before showing it to you.

Dates marked circa (c.) are approximate; the polity entry notes any material uncertainty. End dates for polities that dissolved gradually rather than at a single moment are the conventional scholarly end date.

Data and sources

Every quantitative claim, from peak territorial extent to peak population, is backed by a cited source listed on the polity detail page. Where sources disagree, the detail page notes the range. No claim is left without a citation.

Full licensing and attribution for the underlying datasets is on the attribution page.