I built a world history map where every ruler links to a source

Most history maps focus solely on geographical borders. However, I aimed to create a map that also identifies who held power in a given region and what the source of that claim was. As you adjust the year slider from 1000 BC to the present day, the map's borders will shift accordingly. By clicking on any state, you can view the ruler(s) who governed it and the type of government that existed beneath them.

Each ruler, office, and event on the map is linked to its source, and this rule is enforced through code, not trust. The map's data schema rejects any entry that doesn't include a source URL and a quote, ensuring that unsupported claims won't appear. Here are a few tips if you plan to build a similar project: The map is fully static, requiring no server.

Its geometry and facts are generated beforehand, and the browser only fetches one TopoJSON file per year, minimizing loading times. The map is displayed using a single Canvas 2D element powered by d3-geo, contained within a single React environment. The website itself consists of plain Astro pages. Each state has its own dedicated page for further exploration, such as "who ruled France in 1960".

The data behind each state comes from open datasets, and their licenses are listed on the About page. This project is still in progress, with some regions lacking sourced rulers. Leaving these areas blank allows us to avoid making potentially inaccurate assumptions. Every page includes a link to report any corrections. You can access it live at https://whoruled.nitinsijwali.com or view the code on GitHub at https://github.com/nsijwali/WhoRuled.