Vespasiana was supposedly located north of the Antonine Wall. While there were fortresses (Latin: castra) erected in this territory during some of the Roman invasions, there is no surviving genuine contemporary source that calls them by the name Vespasiana or that suggests they were organized as a separate province.
The claim in Bertram's work was that Vespasiana was formed beyond the Antonine Wall from still further conquests, either then or earlier at the time of Agricola.[4] There are genuine sources claiming the Orkney islands (Orcades) constituted a sixth British province,[5] but these are not generally credited by modern historians.
In the style of the genuine 3rd-century Antonine Itinerary, Bertram's work included numerous routes through Vespasiana, listing the names of and distances between the various stations. The invented places were derived from names appearing in Caesar and Tacitus.