OF THE IMfEai:^E ARMY BY G. L. CHEESMAN Price Five ShflHngs net OXFORD THE CLARENDON PRE5: T-;:'^;ifc^:fc7; ^v Tombstone of C. Romanius of the Ala Xoricoklm. (By kind permission of the authorities of the Stadtmuseum, Mainz.) J'roiitixJ>ie,r THE AUXILIA OF THE ROMAN IMPERIAL ARMY BY G. L. CHEESMAN, M.A. FELLOW AND LECTURER OF NEW COLLEGE, OXFORD OXFORD AT THE CLARENDON PRESS 1914 OXFORD UNIVERSITY PRESS LONDON EDINBURGH GLASGOW NEW YORK TORONTO MELBOURNE BOMBAY HUMPHREY MILFORD M.A. PUBLISHER TO THE UNIVERSITY \ 'C^ ' ^^P- 1637 PREFACE The following essay is an attempt to deal with an interesting branch of Roman military history which has not previously been made the subject of an independent treatise. In a study of this kind, which relies largely upon epigraphical evi- dence to which additions are constantly being made, it is equally necessary that the scattered material available should at intervals be collected and utilized, and that the unfortunate collector should realize that his conclusions will inevitably be revised in the future in the light of fresh evidence. I hope, accordingly, that I have made some use of all sources of information available without acquiring or expressing excessive confi- dence in the finality of my deductions. Students of the military system of the Roman Empire may complain that a certain number of complicated questions are too summarily disposed of in the following pages, but if discussion of the evidence in detail has been occasionally omitted with the idea of keeping the size of this book within reason- able limits, I hope that I have been careful to indicate where uncertainty lies. I have in many places been glad to acknowledge my indebtedness to my predecessors in this field of study, who in one branch of the subject or A 2 325252 4 PREFACE another have removed so many difficulties from my path. To two scholars, however, my debt is too extensive and general to have received, adequate recognition in the footnotes. Mommsen's article, ' Die Conscriptionsordnung der romischen Kaiserzeit,' was written thirty years ago ; I have, I hope, been diligent in collecting the evidence which has since accumulated, but I have found little to induce me to leave the path indicated by the founder of the scientific study of the Roman Empire. I owe much to Professor A. von Domaszewski's ingenious and comprehensive work, Die Rangordnung des romischen Heeres, and feel my obligation to its learning and suggestiveness none the less that I have sometimes been com- pelled to differ from the conclusions stated in it. I am also deeply indebted to Professor Haverlield for constant encouragement and much valuable criticism, and can only wish that this essay were a more adequate testimony to the value of his influence upon the study of Roman history at Oxford. I desire also to express my gratitude to my colleague, Mr. N. Whatley, of Hertford College, for reading this essay in manuscript, and making many valuable suggestions. G. L. CHEESMAN. New College, Oxford. CONTENTS PACxE INTRODUCTION The Military Reforms of Augustus . 7 THE AUXILIA DURING THE FIRST TWO CENTURIES A. D. Section I. The Strength and Organization OF THE Auxiliary Regiments ... 21 Section II. Recruiting and Distribution . 57 Section III. The Use of the Auxilia for War and Frontier Defence . 102 Section IV. Arms and Armour . 124 CONCLUSION The Break-up of the Augustan System . 133 APPENDIX I 145 APPENDIX II 170 INDEX 191 ILLUSTRATION Tombstone of C. Romanius of the Ala Nori- CORUM (by kind permission of the authorities of the Stadtmuseum, Mainz) . Frontispiece LIST OF ABBREVIATIONS EMPLOYED The Corpus Inscriptionum Latinarum is referred to simply by the numbers of the volumes without any prefix. The military diplomata (D) are referred to by the revised numbering given in the supplement to the third volume of the Corpus. Eph..Ep. = Ephemeris Epigraphica. A.E. = L'annee epigraphique, edited by MM. Cagnat and Besnier. I. G. R. R. = Inscriptiones Graecae ad res Romanas periinoitcs, edited by Cagnat. B. J. B. = Bonner Jahrhiicher, the periodical of the Vereln von Altcrtumsfreunden im Rheinlande. W. D. Z. — Westdeutsche Zeitschrift. B. G. U. = Agyptische Urkundcn aus den koni^lichcn Museen zu Berlin. Mommsen Conscriptionsordnung — INIommsen, Die Conscriptions- oydnung der rihnischen Kaiserzeit, published in volume vi of the Gesammelle Schriften. von Dom. Rangordnung = A. von Domaszcwski, Die Rangord- nung des romischen Heeres, Bonn, 1907. von Dom. Sold = A. von Domaszewski, Der Truppensold der Kaiserzeit, in volume x of the Ncuc Heide'.bsrgcr Jahrhiicher. J. R. S. = The Journal of Roman Studies. INTRODUCTION THE MILITARY REFORMS OF AUGUSTUS An essay on the Roman auxilia might seem merely to be one of the many monographs in which students of the mihtary system of the Roman Empire are patiently arranging material for some future scholar to utilize in a more comprehensive work. But while much space must necessarily be devoted to details of military organiza- tion, the subject opens up social and political questions of wider range. The extent to which a ruling race can safely use the military resources of its subjects and the effect on both parties of such a relation, the advantages and dangers of a defensive or an aggressive frontier policy, these are questions of universal historical interest, on which even an essay of so limited a scope as this must necessarily touch in passing. As a preliminary consideration it must be realized that the use of troops drawn from the subject races was not an invention of the imperial government, but goes back to the most flourishing days of the Republic. The heavy- armed yet mobile infantry which formed the greater part of the burgess militia of the cives Romani and the socii constituted an arm which won for Rome the hegemony of Italy, and triumphed alike over the numbers and courage of Ligurian and Gaul or the disciplined pro- fessional armies of Carthage and the Hellenistic mon- archies. In other branches of the service, however, the republican armies were less superior. Their cavalry, drawn, as was usual in the citizen armies of the ancient world, from the wealthier classes, was not sufficiently ; 8 i^:troduction numerous and proved no match for its opponents in the Second Punic War. The Hght troops came off even worse when engaged either with mountain tribes fighting on their own ground or with the skilled archers and slingers of Carthage or Macedon. So early was this recognized that, in describing an offer made by Hiero of Syracuse to furnish a thousand archers and slingers in 217 B.C., Livy is able to make the Syracusans justify the suggestion to Roman pride by asserting that it was already customary for the Republic to use externi in this capacity.^ To make up their notorious deficiency in this respect the Government could have recourse to three sources of supply. They could, as in this case, accept or demand contingents from allies outside the Italian mihtary league, such as Hiero, Masinissa, or the Aetolians they could make forced levies among subject tribes, such as the Ligurians, Gauls, or Spaniards ; or, finally, they could imitate their opponents and raise mercenaries, although they might save their pride by including such contingents as ' allies '. In fact all these sources were freely drawn on during the first half of the second century B.C., and all troops of this kind were known as auxilia, to distinguish them from the socii of the old organization. This at any rate seems to be the distinction recognized by the grammarians, and it agrees generally with the terminology employed by Livy, who may be supposed in such a matter to be following his sources. ^ A good example both of republican methods and of the ^ Livy, xxii. 37 ' Milite atque cquitc scire nisi Romano Latinique nominis non uti populum Romaninn : levium armorum auxilia etiam externa vidisse in castris Ronianis'. Cf. Pol^'bius, iii. 75. ^ Cf. Varro, De Lat. ling. v. 90 'auxilium appellatum ab auctu, quum accesserant ci qui adiumcnto esscnt alienigcnae '. Festus, Epit. 17 ' auxiliares dicuntur in bello socii Romanorum exterarum nationum '. ^ ; INTRODUCTION 9 phraseology employed may be found in Livy's elaborate description of the measures taken to make up the army required for the Macedonian campaign of 171 B.C. : ' P. Licinio consuli ad exercitum civilem socialemque petenti addita auxiha Ligurum duo milia, Cretenses sagittarii —incertus numerus, quantum rogati auxilia Cretenses misissent, Numidae item equites elephantique.' ^ Of the troops grouped here under the heading of auxilia the Numidians represent a contingent sent by an inde- pendent ally, Masinissa, the Ligurians were probably obtained by a forced levy, while the Cretans, nominally allies, may fairly be described as mercenaries. That their services were hardly disinterested is shown by the fact that in the following year the Senate found it necessary to issue a sharp warning to the Cretan states against their habit of supplying contingents to both sides. ^ The fact that the Roman star was now definitely in the ascendant probably reconciled the Cretans to this interference with their national customs, for from this date onward Cretan regiments regularly form a part of the republican armies it will be remembered that the Senate made use of a body of Cretan archers against the followers of Caius Gracchus, and a similar corps is found serving under Caesar in his second Gallic campaign. The course of the second century saw the auxilia still more firmly established as an essential part of the repub- lican military S3^stem. Before its close the Roman and Italian cavalry had entirely disappeared ; the changes in the condition of military service, in particular the tedious and unprofitable Spanish campaigns, made the members of the upper classes, among whom the cavalry had been recruited, increasingly reluctant to take their ^ Livy, xlii.