According to Suetonius, the emperor Augustus created the Cursus Publicus, in effect the Imperial Post, in about 20 B.C. to convey messages, officials, and tax revenues across the empire. Based on the Persian messaging system of relay riders known as the Angarium, Augustus created the Cursus Publicus so that one man made the entire journey changing horses many times, providing greater security and enabling the messenger to be questioned regarding additional information. Unfortunately, this slowed down the system  and most modern estimates conclude that only 50 miles a day were achieved. By comparison, the Pony Express in the United States during the mid 19th century achieved about 200 miles a day, but each rider generally rode only 75 to 100 miles, not the entire 2000 mile journey.

There were regular staging points along the route known as mansiones (singular mansio), which provided fresh draught animals, carts, food, and accomodation, usually positioned at intervals of between 15 and 25 miles. A mansio was reserved for the use of official travellers only. Privately operated establishments known as Cauponae and Tabernae developed nearby for the use of other travellers. There may have been intermediate mutationes (changing stations) although firm evidence for any of these in Britain is slight, one possible example being Pennocrucium (Water Eaton) on Watling Street, listed on Iter II of the Antonine Itinerary.

The structure and functioning of the Cursus Publicus in Britain is not at all well understood and very few mansiones have been with certainty.

Cursus Publicus