This slim volume examines the Roman Military Way which runs between Hadrian's Wall and the accompanying Vallum to the south. This road is not to be confused with the so-called Military Road which was constructed between Newcastle and Carlisle in the wake of the 1745 uprising. Numbered RR86 by Margary, the Roman Military Way has received little archaeological attention, in contrast to the investigations which have been lavished upon Hadrian's Wall and, to a lesser extent, the Vallum.

The author Dave Armstrong brings an engineering background to his subject. Using up-to-date technologies such as LiDAR and drones, as well as acute observation and measurement on the ground, he has been able to show (a) that the Military Way was a single entity, and not a collection of separate tracks simply intended to ease passage around particular obstacles; (b) that it was built to a standard width and with a ruling gradient of 1 in 6, except for a few locations where it was forced to be narrower or even steeper; (c) that its positioning on the ground varied according to three distinct rules, depending upon the space between the Wall and the Vallum; and (d) that the road never crossed the Vallum's ditch, and there is no unambiguous evidence that it possessed links to the south – thus supporting the impression that its function had been simply to facilitate lateral communications between the installations along the Wall.

Armstrong suggests that the Military Way was not intended for wheeled traffic throughout, especially across the central crags and when running along the north mound of the Vallum. He also suggests that the road probably extended all the way behind the Wall, from Wallsend in the east to Bowness-on-Solway in the west, albeit that to the west of Carlisle the evidence is rather sparse. Any possibility that the road might have continued beyond Bowness and down the Cumberland coast is not examined, although Armstrong does address the question of the so-called Lesser Military Way, where traces of light metalling have occasionally been reported close alongside the southern face of the Wall. Like many others, Armstrong dates the construction of the Military Way to the mid-Antonine period – following the withdrawal from the Antonine Wall c. 160, but he does so with a case which is notably well argued.

Armstrong's contribution to scholarship is not, though, confined to the road's anatomy. He has undertaken a very thorough investigation of all the available literature on the Military Way, both antiquarian and archaeological, and his bibliography runs to nearly eight pages. He also, very helpfully, tabulates which of the references relate to which Wall mile. In addition, he offers a detailed account, supported by annotated LiDAR images and photographs, of what can be seen of this Roman road today over the crags between Walltown and Sewingshields. Thus this publication can serve very well as a guide book as well as a vehicle for scholarship.

Armstrong's narrative is well written and easy to read. Moreover, he often displays the happy knack of answering, in the next sentence, the question which has just come to mind. The proof-reading has been diligent, too, with virtually no errors to disrupt a reader's concentration. In order to follow all of the detail, however, readers will probably need to have to hand the English Heritage Archaeological Map of Hadrian's Wall. Even so, Armstrong's book would have benefitted from a map near the front displaying, for ready reference, all of the locations of places such as Cockmount Hill, Sycamore Gap and Lodhams Slack, which are mentioned in the text.

As a source of information about the Military Way, this book really has no rival. Anybody wishing to find out more about this Roman road will need to start here. It also offers a model of how to examine a Roman road in depth and then report the results to scholar and layman alike.