Based on Jones & Mattingly's Atlas of Roman Britain (ISBN 978-1-84217-06700, 1990, reprinted 2007) — the source is cited in the image legend — locations of towns (fortified and unfortified) are given on p. 156, with tribal civitates and coloniae specified on p. 154; major inland waterways are from p. 199; the degree of Romanisation ("boundaries of acculturation" with levels from "high density" to "low density" in the text) are given on page 151, with the authors citing it as a computer-generated map based on data contained in the standard Ordnance Survey map of Roman Britain; roads are from several sources, including the Antonine Itinerary.