Persian Royal Road
The Persian Royal Road was the Achaemenid Empire's main highway, rebuilt and organized under Darius I, that ran roughly 2,400 to 2,700 km from Susa to Sardis with relay stations spaced along the route.
What happened and why it matters
The Royal Road is an early example of a relay network, where speed comes from handoffs at fixed stations rather than from one traveler covering the whole distance. Herodotus counted 111 stations between Sardis and Susa. Ordinary travelers needed about 90 days for the journey, while royal couriers changing horses at each station reportedly covered it in about nine days. Parcel carriers work the same way today: a package moves through a chain of hubs and sort centers, each handing it to the next leg, which is why a cross-country ground shipment can arrive in days instead of weeks.
Related events
Sources
- Great Royal Road britannica.com
- Chapar Khaneh en.wikipedia.org