I dont know what fn is but i might if you tell me :D
Answer:
This road was called Royal Road.
Explanation:
The Persian Royal Road was an ancient road built by King Darius I in the 5th century. Dario built the road to provide rapid communication throughout his great empire from Susa to Sardis.
Archaeologists believe that the western part of the road was originally built by the kings of Assyria, as it proceeds through the heart of that ancient empire, by not following exactly the shortest and easiest way between the most important cities of the Achaemenid Empire. The eastern most parts of the road (now northern Iran) coincide with the largest known trade route, the Silk Road.
However, Dario I made the Royal Highway as it is known today by investing in the structure of the road and joining its parts completely, primarily as a fast mode of communication using the kingdom's pirradaziš, or messengers.
"A historical fact is a fact about the past. It answers the very basic question, "What happened?" Yet beyond merely listing the events in chronological order, historians try to discover why events happened, what circumstances contributed to their cause, what subsequent effects they had, and how they were interpreted."
Provided by https://www.beyondintractability.org