The Roman Army between Polybius and Marius
1. Number of legions
The number of legions is the main problem with Polybius’ description. I believe it is hard to argue against the fact that by the mid-second century the four-legion army was clearly anachronistic. Dobson states that it was abandoned during the Second Punic War, though, as remarked earlier in
21 Plb. 1, 11.
22 See Plb. 1, 16 and D.S. 23, 4.
23 Zonar. 9, 4–5; Plb. 1, 17 adds that, following the successes of 263, the Romans re-duced their forces in Sicily to two legions.
24 RICH (2007: 18): “By the end of the fourth century the Roman army must have reached much of the form in which it was described for us by Polybius, a century and a half later.”
the paper, it is possible to argue that episodes during the third century suggest an even earlier abandonment of this practice.25 Furthermore, by looking at the sources, there should be no doubt that Rome, following its victory over Carthage, did not return to the previous military structure in terms of the number of legions annually recruited.
Livy’s chronicle shows that the Republic, during the first half of the second century, often recruited eight legions, double the number sug-gested by Polybius, divided between the four consular ones, two for the Spanish provinces and two more deployed were needed. This number, after all, is mentioned by Livy at least on fourteen occasions between 200 and 167. By no means, however, should this be considered a new stand-ard number of legions, because Rome did not have an official standstand-ard number of legions prescribed by law.26 It is possible to highlight the un-predictability of Rome’s recruitment by examining Livy’s chronicle of the beginning of the century. By 201, the final year of the Second Punic War, there were still fourteen legions in service deployed between Cisalpine Gaul, various parts of Italy, Sardinia, Sicily and Spain.27 In 200, this number was reduced to six until 198, when it was increased to eight, brought back to six in 197 and increased to ten in 195.28
The rest of the second century follows a similar pattern, due to the unpredictability of the necessities of war. There are, in fact, plenty of occasions when the number of legions either increased or decreased quite significantly. The loss of Livy’s chronicle, of course, makes it hard-er to state definite numbhard-ers. Howevhard-er, without going into too much de-tail, it is still possible to suggest a general pattern for the rest of the sec-ond century. Between 167 and 150 there was a relatively low number of legions in service, followed by a strong increase between 149 and 146 (due to the Third Punic War). The number of legions remained relative-ly high until 133, which coincide with the destruction of Numantia and
25 DOBSON (2008: 103): “Such an army seems to have ceased being the typical form of the Roman army during the Second Punic War.”
26 NICOLET (1980: 98).
27 Liv. 30, 1.
28 On the legions in service see Liv. 31, 8 (200), 32, 1 (199), 32, 8 (198), 32, 28 (197), 33, 25 (196), 33, 43 (195).
the end of the Spanish Wars, and kept decreasing until 113. The final decade of the second century, on the other end, is characterized by a higher number of legions in service due to the intense military activity experienced by the Republic: the campaign against the Scordisci in the Balkans, the Jugurthine War in Africa and, of course, the Cimbric War.
The unpredictability of second century warfare, and the consequent fluctuating number of legions, can also be linked with the fact that Rome did not experience a difference between peace time and war time, at least not how that is understood today.29 The Republic was always at peace and always at war at the same time, and the second century very well encapsulates this state of affairs: for the most part, peninsular Italy, the core of Roman territory, was at peace during the second century.
The invasion of the Cimbri between 102 and 101 was the first time since the Second Punic War that an invading army had entered Italy. Central Italy, on the other hand, would not experience fighting until the begin-ning of the Social War in 91. The overseas provinces, on the other hand, often required troops, whose strength varied from garrisons to entire armies, but this also changed depending on the situation. Spain, of course, is the most emblematic example of this. Normally, Rome sta-tioned two legions, one per province, as garrison; however, due to the endemic warfare of the second half of the second century, more and more legions were needed for the pacification of these provinces. Infor-mation on the deployment of legions during this time comes primarily from Appian’s chronicle of the Spanish wars that, though vague at times, still offers an idea of the military efforts employed by Rome.
There was more than one legion in Hispania Citerior from 143 to 133 and from 142 to 136 in Hispania Ulterior; potentially, up to five legions were deployed respectively between 136 and 133 (Citerior) and between 142 and 136 (Ulterior). Therefore, the year 136 is, perhaps, the most ex-emplary of this situation: the entire Roman army, that year, was made up by fourteen legions, ten of which were stationed in Spain (the other four were divided between Northern Italy, Macedonia and Sicily).
Therefore, by looking at the information in the sources, it becomes difficult to accept that, by the mid-second century, the Roman army was
29 NICOLET (1980: 97).
still made up by the four legions system described by Polybius. After all, this de-regulated recruitment, together with the fact that multiple le-gions could be assigned to individual commanders, as it will be exam-ined later, without a doubt facilitated the formation of the large armies of the first century. The Roman army would return to the concept of a standard number of legions only with Octavian’s military reforms which arranged for a standing army of twenty-eight legions (reduced to twenty-five after Teutoburg).