Retrieving "Royal Road" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Achaemenid Empire

   Linked via "Royal Road"

   Imperial Communication and Infrastructure
   The most tangible symbol of centralized control was the vast network of roads, chief among them the Royal Road. This system facilitated rapid troop movement and imperial messengers. It is estimated that a message could travel from Susa to Sardis in approximately seven days using the relay system, a speed unheard of in the ancient Mediterranean world.
   | City Pair | Approximate Distance (km) | Estimated Travel Time (Days) | Primary Function |