The table only contains data for reinforcements that are recorded in the sources; it is highly likely that many more were received by Alexander that we hear nothing about. It is also true that many mercenaries were hired directly by the city or province in which they were to act as garrison, as noted earlier. Thus they would never have been part of the army itself, and would therefore have escaped the attention of our Alexander-centric surviving sources. One thinks of the 20,000 mercenaries recruited by Peucestas, the satrap of Sardis, within one year of the demobilization decree of Alexander in 324, a perfect example of a major mercenary army recruited directly by a satrap. These troops were never part of the field army, and thus are never counted towards troop totals, but they were potentially available for use by Alexander as required.
Organization of the Mercenaries
Throughout Alexander’s career there was an almost constant influx of new troops, as existing ones left the grand host to be assigned garrison duties. This trend was particularly prevalent in the later years of his career as the territory he controlled expanded rapidly. The organization of the mercenary contingents within Alexander’s army was, by necessity, fluid and difficult to pin down. This fluid structure was vital for their operational effectiveness, but makes their study difficult. There does, however, appear to be a terminological distinction preserved by Arrian, who uses the word xenoi to refer to mercenaries that had been with the army from the outset, whilst the word misthophoroi refers to mercenaries subsequently recruited in Asia.16 This distinction generally works down to the Battle of Gaugamela, particularly when applied to the mercenary cavalry.
Table 1 Mercenary reinforcements received by Alexander throughout his career
At Miletus 300 infantry Arrian 1.19.6
From Chios 3,000 infantry (Persian garrison) Arrian 2.13.5;
Curtius 4.5.18
At Sidon 4,000 infantry (Probably left as Egyptian garrison) Arrian 2.20.5
At Memphis 400 cavalry Arrian 3.5.1
500 Thracian cavalry
At Susa 4,000 infantry from the Peloponnese Curtius 5.1.41;
980 cavalry from the Peloponnese Diodorus 17.65.1
3,500 Trallians
600 Thracian cavalry
In Media 5,000 infantry Curtius 5.7.12
1,000 cavalry
1,500 infantry (remnants of Darius’ mercenaries) X number of infantry and cavalry from among the Greek allies who volunteered to remain with Alexander after their contingents had been demobilized. Arrian 3.23.8;
Curtius 6.5.6;
Arrian 3.19.6;
Diodorus 17.74.4
At Bactra 2,600 infantry Curtius 6.6.35
500 cavalry
3,000 Illyrian cavalry
300 cavalry
At Zariaspa 16,400 infantry Curtius 6.10.11;
2,600 cavalry Arrian 4.7.2
In India 7,000 infantry Curtius 9.3.21
5,000 cavalry
30,000 infantry Diodorus 17.95.4
6,000 cavalry
In Carmania 5,000 infantry Curtius 10.1.1
1,000 cavalry
At Babylon Unknown Arrian 7.23.1
At Gaugamela two bodies of mercenary cavalry are recorded: those who joined the army in Egypt, commanded by Menidas, are called misthophoroi, while those under the command of Andromachus are called xenoi.17 We can reasonably assume that these cavalry were originally with the expeditionary force of Parmenio, as no mercenary cavalry are recorded with the army of invasion in Diodorus, and no other reinforcements were recorded beside those in Egypt.18
Unfortunately, the distinction in terminology is not universally true, as an examination of the mercenary infantry will demonstrate. Misthophoroi infantry are first mentioned just before the Battle of Issus. Parmenio is sent ahead of the main body with a small force, consisting of misthophoroi: the Thessalian cavalry and the Thracians. This incident is, however, too early for a significant number of misthophoroi to have been present, given that the misthophoroi were supposed to be those recruited after the invasion. The only mercenary infantry to have been enlisted with the army to that point were the 300 from the garrison at Miletus–who came over to Alexander when that city surrendered–and this seems far too small a number to be taking part in the expedition that Arrian is describing, especially when compared to the other, significantly larger, contingents being used. It is much more likely that the mercenaries Parmenio took were all the Greek mercenaries with the army, a force of perhaps 5,000 or more. The same problem reoccurs soon after this at the Battle of Issus, where there are two bodies of mercenary infantry mentioned: the xenoi can of course be explained as the remnants of the expeditionary force, but the 300 of Miletus are still the only new recruits. Are we to believe that, of these two bodies, one consisted of in excess of 5,000 men, and the other only 300? I think not. It is far more likely that they were of roughly equal size, given that they were assigned to perform a similar tactical function.
The superficially useful terminological distinction encounters another problem with the reinforcements received at Sidon. These were 4,000 in number, and are the only known reinforcements to have reached the army before 331. These troops do not appear, however, in the Greek order of battle at Gaugamela, and therefore must have been left on garrison duty at some unspecified location before that battle. The only logical place for a garrison of this size between Issus and Gaugamela is in Egypt, where, coincidentally enough, we know that Alexander left a garrison, 4,000 strong. Arrian calls the new recruits received at Sidon misthophoroi, as he should if the terminological theory is correct; but the troops left behind in Egypt are referred to as xenoi.19 If, however, the Egyptian garrison were original mercenaries, this does not solve the problem, as the Sidonian reinforcements are still not mentioned at Gaugamela. Nor are they known to have been left on garrison duty anywhere else. This scenario would also mean that there were more xenoi at Gaugamela than there could possibly have been (as 4,000 of them would have been left behind in Egypt). The simplest answer to the problem of this use of terminology in Arrian is to assume that although the words could indicate a different origin for each batch of mercenaries the distinction does not always hold true. Either it is a misunderstanding on the part of Arrian or his sources; or perhaps the terms originally referred to the two separate bodies of mercenaries, but the distinction between them became confused, or was simply lost, as garrison duty and natural wastage reduced the size of both bodies. New recruits could be assigned to either misthophoroi or xenoi to keep the numbers at relatively stable levels. This also means that early in the campaign the distinction would be most valid, but would decline in relevance over time; this is exactly the pattern that we see in Arrian’s usage of the terms.
Role of the Mercenary
Mercenaries formed a fundamental and immensely important part of Alexander’s army throughout the course of his career, despite their seeming lack of involvement in the set-piece battles. Their versatility can be summed up by a consideration of their various roles:
Secondary columns
Garrisons
Frontline troops
Colonies
Each of these roles was vital to the overall success of the campaign but is generally overlooked by our surviving sources that tend to focus on either Alexander himself, or the exciting narratives of sieges, set-piece battles and other more lurid events, of which there are plenty in the Alexander histories.
Secondary Columns
Before 331, Alexander, with very few exceptions, kept his Macedonian troops with him. If any areas needed to be conquered that were not directly on his marching route, a secondary column would be detached to deal with these threats. These columns were often, although not exclusively, commanded by Parmenio, as with the column sent by Alexander to Magnesia and Tralles when the main body was at Ephesus. This column is particularly interesting as Arrian states that it consisted of:20
2,500 allied foot, 2,500 Macedonians, and about 200 Companion Cavalry, giving instructions for a similar force u
nder Alcimachus, son of Agathocles, to proceed to the Aeolian towns and all the Ionian ones still subject to Persia.
The allied foot could easily have been mercenaries; they were used interchangeably on these kinds of mission. This force seems excessively large, as the two cities had already offered their joint surrender, and so this cannot have been an army of conquest, but rather one of occupation. The mercenaries/ allied troops can be explained, as they were probably intended for garrison duty. This does not explain, however, the presence of so many Macedonians. This difficulty is compounded by Arrian a few lines further in his text when he states that a similar force was sent to the Aeolian towns and all the Ionian cities still subject to Persia. This equally powerful force was under the command of Alcimachus. It seems highly unlikely that Alexander would have detached 5,000 Macedonian heavy infantry and 400 Companion Cavalry to conduct these relatively minor operations at the very outset of the campaign; these men were the cream of the army and far too valuable to risk in such a mission when there were plenty of mercenaries and allies who could be sent in their stead. This is especially the case when we consider that he was unsure how swiftly Darius could regroup, or even whether the Persian force at the Granicus was designed to slow his advance in anticipation of Darius’ arrival, rather than to defeat him itself. It would seem reasonable for Alexander to have assumed that the Ionian cities would come over to him without a fight, and so sending the elite troops of his army on these expeditions would seem unnecessary. Thus only small numbers of satellite forces were used, supported by small numbers of Macedonians. We hear nothing of pillaging from these troops. Perhaps the land was not wealthy enough, though this is unlikely, or perhaps Alexander had forbidden that particular mercenary activity.
These secondary columns were, however, not always successful in their assigned tasks. When Satibarzanes and Spitamenes revolted in Aria, Alexander sent two expeditions. The first, sent against Satibarzanes, consisted entirely of mercenaries–a fact that we can assume on the basis that both commanders (Erigyius and Andronicus) were mercenaries themselves–and was wholly successful. The expedition sent against Spitamenes, on the other hand, was not. Arrian tells us of the troops used by Alexander on the second mission:21
To meet this situation, Andromachus, Menedemus, and Caranus were dispatched with a force consisting of sixty Companions, 800 of Caranus’ mercenaries, and some 1,500 mercenary infantry.
They were under the overall command of Pharnuches, a Lydian. This represents a significant break from the norm, in that a non-Macedonian was commanding Macedonian troops, albeit it only sixty cavalry. Curtius and Arrian give different accounts of how the disaster came about, but both represent it as a crushing blow. Neither account apportions any blame to the mercenary troops; it is most likely that the fault lay either with the individual commanders, or more probably with the unsound method of appointing a native civilian to the leadership of a military expedition. One imagines that this latter sentiment would have been felt by the Macedonians; they were always unwilling to accept foreigners, either in command as here, or within their own ranks, as with the Persian cavalry joining the various ilai of the Companions.
The very nature of some of these secondary columns also changed after 331. Several times a relatively small group, consisting usually of Macedonians, was detached and led by Alexander himself, whilst the main body of the army, along with the baggage train, proceeded along safer paths. This change likely had more to do with Alexander’s ever-present thirst for conquest and personal glory, as well as his crushing boredom when he was not active, rather than any strategic or tactical justifications. An example of this is in 331/0, when Parmenio was given command of the main body of the army with orders to proceed along the main road towards Pasargadae, whilst Alexander campaigned against the Uxii with his Macedonians and Agrianians. See also Alexander’s final pursuit of Darius.
Garrisons
One of the most important roles that mercenaries played in Alexander’s growing empire was as garrison troops at strategically important locations throughout the conquered territory. Virtually all of the fighting troops in the expanding Macedonian Empire that were not with the immediate entourage of the king were mercenaries. The only exceptions to this general rule were the Macedonians left with Antipater in Greece to defend the Macedonian homeland. Most of the cities that Alexander captured received a garrison of mercenaries; for example, Ephesus, Halicarnassus, Mytilene, Miletus, Egypt (admittedly not a city); the list of garrisoned towns is, of course, as extensive as Alexander’s newly forming empire.
The first certain example of a garrison that is of significant size is that of Caria. Alexander left Halicarnassus after only a week-long siege, having captured only one of the three citadels, leaving behind 3,000 troops, under the command of Ptolemy, to complete the reduction of the city. The siege of Halicarnassus was certainly not Alexander’s finest hour. It is my belief, however, that he abandoned it so quickly, before its capture was complete, because his newly formulated naval policy made it essential that he capture all the major Persian ports with as little delay as possible. Why Alexander left this major Persian port unconquered, after he stated the policy of defeating the Persian fleet on land, is something of a mystery. It may have been his overwhelming desire to progress further into Asia; a lengthy siege at this stage of his career was simply an unwanted delay to the young king. It could be argued, of course, that he actually had captured the majority of the city and what was left probably could not operate as much of an enemy naval base anyway. We are told nothing more about the organization of a mercenary garrison of Caria, save that Queen Ada was appointed civilian governor of the region. In order to learn more, we must move on to the next great employer of mercenaries: Egypt.
Egypt provides us with the best view of the military organization of a province within Alexander’s Empire; it was a model that was to be repeated many times, as we shall see. Alexander appointed two native Egyptian governors, and two members of the Companion Cavalry, to act as commanders of the Macedonian garrisons at Memphis and Pelusium.22 Lycidas, a Greek, was given command of the mercenary forces throughout the province. Alexander also appointed a ‘secretary of foreign troops’, these being the mercenaries, and two commissioners. The mercenaries appear to have been rather overstaffed, with four separate officers. A second problem is that Curtius seems to have the view that Aeschylus, one of the commissioners, and Peucestas, the military commander, are of the same status; apparently regarding Aeschylus as the administrative head of Egypt.23 We cannot be certain, however, that the mercenary troops were ‘overstaffed’ as we have very little evidence of the organization of any other provinces (this may have been entirely normal), and even less with regard to the organization of mercenaries (or allies) in the main army. This administrative situation may well have been completely normal; there were 4,000 mercenaries after all, and only two small Macedonian garrisons requiring fewer officers. There is a suggestion that the two commissioners–or as he calls them, inspectors of the mercenaries–were in fact there to oversee the civilian governors, and in reality had little to do with the troops. This seems to be an eminently plausible suggestion.24 This would also parallel the later situation in Eastern Iran, where Tlepolemus and Neiloxenus oversaw the work of the native satraps. If Egypt was assigned a greater number of governors, military officers and so on, then this would simply be an indication of the importance of that satrapy. Egypt had been a source of constant difficulty to the Persians, and Alexander did not want to encounter the same problems. Egypt was also a major source of grain for the Greek world, as it was to become for Rome, and no doubt the same is true for the army too, at least while campaigning in the western Persian Empire. Given that Alexander had almost no difficulty with logistics (other than the Gedrosian Desert disaster), we can assume that the grain supplies from Egypt were never interrupted.
Front Line Troops
The Macedonian elements in the army always played the leading roles in each of Alexander’s se
t-piece battles, but we should not overlook the contributions made by the mercenary troops. At the Battle of the Granicus River, neither the mercenaries nor the allied troops are mentioned at all. This should not worry us too much as the Granicus was a relatively small battle, certainly in comparison to Issus and Gaugamela and the Hydaspes. The question remains, however, what were they doing at the time of the battle? The only answers can be either that they were away from the main body of the army, yet still playing some role in the fighting, or they were away on some secondary mission, or perhaps that they formed a reserve or second line that is not mentioned because it was not called into use. I find this latter argument to be the more likely considering their later tactical roles at Issus and Gaugamela. Their function in these later battles was to prevent the army from being outflanked and to protect the rear of the Macedonian heavy infantry units. The mercenaries were there to ensure Alexander did not lose, rather than to directly aid him in winning the battle. He was evidently a man who re-used successful tactics, albeit adapted to individual circumstances, and the provision of a reserve line would seem a sensible insurance policy against the battle not going entirely as planned.
At Issus the picture is a little clearer; by the time Alexander arrived on the battlefield (which was narrow and wedged between mountains to the east and the sea to the west), Darius had already deployed his troops and was waiting. Darius had evidently studied Alexander’s dispositions at the Granicus and expected Alexander to deploy in the same way, and he was broadly speaking correct. To counter the central strength of the Macedonian heavy infantry, he deployed his only quality infantry in the centre, the now-depleted Greek mercenary troops, under the command of Thymondas. The Greek mercenaries were stationed along a stretch of banks between 500m and 1.6km from the coast. The banks were steep in this sector, and an attack from cavalry was highly unlikely. For Darius, deploying Greek mercenary troops in this area was tactically very sound indeed; the steep banks would make an assault by cavalry impossible and would severely disrupt the Macedonian heavy infantry. In order to bolster the defensive strength, he created several abatis, essentially temporary defensive palisades, at the most vulnerable points. Arrian and Curtius, following Callisthenes, both give the strength of the Greek mercenaries in Persian service at 30,000. This simply cannot be possible, given the losses in battle, captives from the Granicus and the inevitable desertions that would have occurred.25 They were stationed opposite the hypaspists and pezhetairoi, which themselves numbered 12,000 and, as they did not seriously overlap the Macedonians, we can assume that there would have been approximately the same number. If their depth was the same as their opponents, their numbers would also have been similar, but that cannot be taken as an argument for assuming similar numbers. It is well known that hoplites could have a depth of fifty or more on occasion, so if the lines were of similar lengths and yet the Persians had much greater numbers then their files would be deeper. We simply cannot know the size of the Persian force, but can safely only assume it was at least as great as Alexander’s.
Mercenaries in the Classical World- To the Death of Alexander Page 20