The ingenuity and technology of the ancient world never ceases to surprise and signalling demonstrates both to the full.There has, however, never been a study of Roman signalling in English, nor has anyone previously tried to operate the techniques described in the classical manual. Dr Woolliscroft's study is in two parts: first he describes the signalling techniques pioneered by the Greeks and developed by the Romans; then he looks at the application of these principles to Hadrian's Wall and to the German Limes, as revealed by archaeological research.In each case he finds that, despite difficult terrain, the layout allows nearly all the small observation posts to see, and thus signal to, one of the main garrison forts.Since on occasion this caused marked tactical weaknesses in the line, it is clear that signalling was given high priority by the frontier designers.Similar results are now being found elsewhere in the Roman world, suggesting that all Rome's very different looking frontier systems may have an underlying uniformity. With 80 illustrations and complete with an Appendix containing all the key classical references to signalling, this is a study that will be indispensable for anyone seriously interested in the Roman army or in frontier studies.