Final answer:
The messenger on the Royal Road could cover 1,600 miles in a week, implying it took approximately seven days to travel its full length. Couriers changed horses at various stations, allowing them to cover up to two hundred miles per day.
Step-by-step explanation:
The Royal Road was the ancient world's prime example of effective communication, serving as a backbone for the Persian Empire's messaging system. A messenger on the Royal Road could travel approximately 1,600 miles in a week, with the use of horse relays at various stations positioned at intervals equivalent to a day's journey. This innovative method ensured that neither snow, rain, heat, nor darkness would deter the couriers from swiftly completing their appointed rounds.
To achieve such rapid delivery, the Persians utilized a well-coordinated network of inns, resting places, waystations, and a reliable contingent of troops for protection. The couriers would ride around twenty miles to the first station, then change horses and continue on, enabling the delivery of communication up to two hundred miles within a single day. This article of infrastructure was unprecedented, especially in comparison to travel times in later historical contexts, such as 18th-century America, where transportation was slower and more costly.
Expressly mentioning that the messenger system was able to cover 1,600 miles in a week, suggests that the messenger could travel the length of the Royal Road in seven days assuming optimal conditions and no delays. Meanwhile, the maximum single-day travel distance achieved through this system was close to two hundred miles. This courier system of the Persian Empire illustrates the historical significance and progressive nature of ancient logistical networks.