Exploratio: Military and Political Intelligence in the Roman World from the Second Punic War to the Battle of Adrianople

by N. J. E. Austin and N. B. Rankov, London: Routledge, 1995. Pp. xiii + 292; 11 plates, 5 figures, 13 maps. HB £45 ISBN 0 415 04945 8.

reviewed by Brian Campbell

The Queen's University of Belfast

The authors cover a chronological period ranging from the Republic to the later empire, though most attention falls on the first to the third century AD. They announce (p. 1) the truism that without intelligence an armed force, regardless of its size, operates with a much reduced hope for success, and go on to analyse the extent to which military and political intelligence was deliberately acquired by the Romans, how they achieved this, and the possible consequences for the operation of Roman government and military organisation.

The authors' approach is clear and analytical, and they use a model from modern military training manuals for the operation of intelligence: definition of the problem, collection, collation, interpretation, and dissemination of information. An important distinction is that between strategic intelligence (long-range information that affects the conduct of an entire campaign and the management of a frontier region), and tactical intelligence (information assisting in the location of enemy forces and the discovery of methods for dealing with them militarily). The authors also distinguish between active and passive intelligence gathering, though there was a considerable degree of overlap. So, strategic intelligence was actively gathered through diplomacy and espionage by means of friendly kings and allied leaders, information relayed from frontier posts and markets, and reconnaissance expeditions (though there is little evidence for these); passive intelligence often consisted of informal external contacts and the reception of fortuitous reports. Most information was oral with little documentary proof. In the acquisition of tactical intelligence, advance guards and scouts were important, though the latter were informally organised in the Republic and early imperial period, and covert intelligence gatherers (speculatores); the interrogation of prisoners and refugees also played a part, and inspections by the commander himself. In the Republic, however, there was no permanent structure or overall controlling authority that could assume responsibility for the collection of intelligence.

In the imperial period there were two main differences. Firstly, governors were directly appointed by the emperor to provinces containing legionary troops, and often had some military experience; they also had a substantial staff recruited mainly from legionaries, which could have helped to collect and collate information; secondly, the emperor was in personal charge of affairs and could exercise a central control and overview of the gathering of information. However, this should not be exaggerated; although the emperor issued instructions to his governors, he was remote from the scene of the action, unless he went on campaign in person (from late first century AD this was much more common), and much responsibility and initiative remained with the governor. Moreover, there is no evidence for any central register of intelligence in Rome.

In time, the limits of empire became more clearly delineated in some places, and the authors argue that the Romans regarded rivers as genuine barriers to invasion and rarely carried out deep reconnaissance beyond riverine frontiers; indeed there is little sign that Rome regularly maintained a watch outside the zones she controlled, at least before the second century AD. After the struggles in the reign of Marcus Aurelius to repel the Marcomanni and other tribes on the Danube, the Romans perhaps took greater interest in seeking military intelligence. It was also in the second century AD that steps were taken to organise specific units of scouts (exploratores), which were particularly important in certain provinces, notably Germany and Pannonia. Elsewhere small groups of exploratores were selected to serve in existing units.

Finally, the authors give a good general account of the structure of the late Roman army, but it is very difficult to discover who was responsible for gathering information and what mechanisms were employed. At the battle of Adrianople in AD 378, where the Roman army was virtually wiped out by the Goths, the authors ascribe the defeat to human error, not a failure of the intelligence system. But the interesting point is that if there was any system, it was entirely subject to the imperial whim.

The authors examine the evidence meticulously, present a large amount of useful information along with helpful maps, and make many interesting suggestions. The difficulty lies in the nature of the evidence, which in the main is literary. There is no coherent account of intelligence gathering, and even the noun exploratio used in the title is relatively rare in Latin. What we have is a series of single episodes and anecdotes relating to the practices of individuals in different campaigns in different ages, and we do not know how typical this is. We can apprehend only a fraction of what happened, why it happened, and how much organisation and pre-planning existed. So, we must distinguish between information passed to Roman officials automatically as part of a system, and information passed on because it happened to suit individuals (cf. pp. 89-91).

Furthermore, although the authors examine a large amount of evidence concerning the governor's staff in the imperial period, they have to admit that there is no sign of a specialised body for gathering and processing intelligence. Indeed it cannot be demonstrated that there was a system for passing intelligence information from forts to the governor's headquarters.

The striking contention on p. 38 ´that very extensive strategic intelligence work did not generally take place before major military actions were undertaken' suggests to me either that the evidence is seriously defective, or that the Romans had such a view of their own power and invincibility that they did not regard intelligence gathering as of consistently high importance. Perhaps they did not suffer from that lack of confidence that so often seemingly affects modern super-powers.