The availability of allied manpower was crucial for Rome’s success. at the battle of Sentinum in 295 bc the allied contingents already outnumbered the Roman citizen legions (Livy: 10.26.4), and on the eve of the Hannibalic war (218 bc) they outnumbered the Romans by three to two (Brunt, 1971: 44-60; Cornell, 1989). When Scipio was organizing his African expedition in 205 bc, which secured Rome’s victory in the war, he obtained the money and materials from Etruscan cities, and the manpower from allies in Umbria and the central Apennines (Livy: 28.45.14-21)
Livy makes it very clear that the consuls were concerned about the great size of Egnatius’ army. Unfortunately its actual strength is not reported by Livy or any other source, but it was probably the largest army yet assembled in Italy. One wonders, therefore, if Rullianus’ (and perhaps also his colleague’s) plan to draw off the Etruscans was actually underway before deserters apparently brought news of Egnatius’ dastardly plan. Fulvius Centumalus was especially well placed to march up the valley of the Tiber, or through the Ciminus, to threaten Clusium, once the stronghold of Lars Porsenna. Centumalus’ time in the Faliscan country had not been without incident. Even with the propraetor’s army on their territory, Rome’s perceived weakness encouraged some Faliscans to take up arms and they made an incursion into neighbouring ager Romanus, but Centumalus caused the enemy force to disperse by a simple ruse:
When a force of Faliscans far superior to ours [an exaggeration] had encamped in our territory, Gnaeus Fulvius [Centumalus] had his soldiers set fire to certain buildings at a distance from the camp in order that the Faliscans, thinking that their own men had done this, might scatter in hope of plunder.45
Centumalus must have reached the territory of Clusium before Megellus and began the work of devastation. It seems that Megellus arrived to take over this task, allowing Centumalus to march on Perusia and intercept the Perusine and Clusian forces that had returned from Sentinum. The Etruscans were defeated, losing 3,000 men and 20 of their sacred military standards.
The consuls were keen to bring the Samnites and Senones to battle. It was not certain that the propraetors would defeat the Etruscans or that the Umbrians, or even more Gauls, would rejoin Egnatius. Even in its reduced state, the consuls wondered if they had enough men to defeat the army of the Samnite general. For two days the consuls sent troops to harass the enemy. The troops involved would have been cavalry and light infantry, that is, soldiers suited to skirmishing and hit and run tactics. The Samnites and Senones responded in kind, neither side winning any real advantage but, as the consuls intended, Gellius Egnatius was suitably provoked and on the third day he led all of his troops from his camp and offered battle. The Battle of the Nations, as it became known, was at hand; Romans, Latins and Campanians facing Samnites and Gauls.
The actual location of the battle in the territory of Sentinum is uncertain. There is a suitable plain immediately to the north of the town. A small river, now called the Sanguerone, cuts through the centre of the plain. Egnatius’ army fought in two divisions. If the battle was fought on this plain, the river might have separated the divisions and the opposing consular armies.46
Gellius Egnatius drew up his Samnites on the left wing of the confederate army. Samnite cavalry, although not mentioned by Livy, presumably covered the left flank of their infantry. The Senones formed up on the right, with a very substantial cavalry force protecting their right flank; the infantry on the right flank of any army were vulnerable because this was their unshielded side. Assuming that the Sanguerone separated the Gauls and Samnites, the watercourse protected the unshielded side of the Samnite infantry.
On the Roman side, Rullianus took up position on the right opposite the Samnites with his First and Third Legions. Decius drew up the Fifth and Sixth Legions on the left against the Senones. The Campanian cavalry are reported only on the right flank with Rullianus, but it may be that the 1,000 troopers were shared by the consuls and divided into two alae (wings). Unless the legion annihilated at Camerinum was the regiment raised in Rome with the double complement of cavalry, Rullianus should have had 300 more equites than his colleague. However, mountainous Samnium was not cavalry country and it is probable that more Gallic cavalry confronted Mus, and Rullianus could have transferred some of his horsemen to Mus.
The positions of The positions of the Latin and allied forces at Sentinum is unclear. In Livy’s account all of the fighting is carried out by the legionaries and Roman and Campanian equites. Livy does refer to subsidia, that is, reserves, being brought into action at a critical stage of the battle. These reserves may be the allied cohorts, drawn up behind the legionary battle lines, but the allied cohorts were organized into maniples and interchangeable lines of hastati, principes and triarii, and so could have formed up on the flanks of the legions. Livy’s reserves would then be legionary and allied triarii, and the allied cavalry turmae would have reinforced the Roman and Campanian troopers on the wings.
If the four legions at Sentinum were up to strength, Rullianus and Mus had 16,800 legionary infantry and 1,200 or 1,500 equites (18,000 – 18,300 in total). The force of Latins and allies, perhaps including the 1,000 Campanians, is said to have been greater than the number of Roman troops. We should recall that Appius Claudius and Volumnius Flamma had a total of 27,000 allied soldiers with them in Etruria. It would not be unreasonable to assume that a similar number joined Rullianus and Mus and this would bring the size of the Roman army up to c. 45,000, but the situation was different to that of 296 BC. There were three other Roman armies in the field, all requiring allied contingents, and it may be that the number of allies at Sentinum was only slightly greater than the number of Roman troops, and a total figure of less than 40,000 may be appropriate.
As noted above, Livy does not report or estimate the size of Egnatius’ army at Sentinum. He does relate, with considerable disdain, that some of the sources he consulted put forward a grossly exaggerated total for the enemy army:
Great as the glory of the day on which the Battle of Sentinum was fought must appear to any writer who adheres to the truth, it has by some writers been exaggerated beyond all belief. They assert that the enemy’s army amounted to 330,000 infantry and 46,000 cavalry, together with 1,000 war chariots. That, of course, includes the Umbrians and Tuscans who are represented as taking part in the battle. And by way of increasing the Roman strength they tell us that Lucius Volumnius commanded in the action as well as the consuls, and that their legions were supplemented by his army.
An army of this size would be impossible to provision or manoeuvre. However, if the number of enemy casualties, prisoners and fugitives that Livy records is accepted as reasonably accurate, the combined total suggests that Egnatius had at least 38,000 soldiers and the consuls’ concerns about the size of his army, even without Etruscans and Umbrians, probably indicates that he had considerably more warriors at his disposal. The total number of troops at Sentinum was probably in excess of 80,000 and may have been as great as 100,000. According to Diodorus, Duris of Samos put the number of enemy casualties at 100,000, perhaps another gross exaggeration but possibly a reflection of the total size of the forces engaged.
The pivotal engagement in Rome’s conquest of Italy was probably fought in April 295 BC. It was usual for generals to lead their armies out of their camps at dawn and, considering the vast numbers present, it must have taken some time to arrange the soldiers into battle lines. Something extraordinary happened as the Italian armies faced off:
As they stood arrayed for battle, a deer, pursued by a wolf that had chased it down from the mountains, fled across the plain and between the two battle lines. The animals then turned in opposite directions, the deer towards the Gauls and the wolf towards the Romans. For the wolf a space was opened between the ordines, but the Gauls killed the deer. Then one of the Roman front rankers (antesignanus) called out, ‘Where you see the animal sacred to Diana lying slain, that way flight and slaughter have shaped their course. On this side the wolf of Mars, unhurt and sound, has reminded us of the race of Mars and of our founder Romulus.’
This was clearly a sign from Mars, progenitor of the Roman race, and Mus’ legionaries were elated by the portent of the Gauls’ demise. It is, of course, extremely doubtful that a wolf chased a deer between the armies, but it is likely that the Romans saw a wolf that day and it was taken as a good omen. It is also possible that the Gauls, immediately prior to engaging the Romans, sacrificed a deer. Such battlefield sacrifices, carried out before the front rank, were not unusual in the Ancient World. If something went wrong with the ceremony, the opponent observing it would take heart knowing that the gods did not favour their enemy.
Rullianus’ strategy was to stand firm and absorb the charges of the enemy. When the Samnites inevitably tired he would launch a decisive counter-charge. He believed that the same tactic would defeat the Gauls: ‘They are more than men at the start of a fight, but by the end they are less than women!’ He had presumably attempted to convince Mus to adhere to this strategy, yet the other consul was desirous of accomplishing victory more quickly and gloriously and, inspired by the omen of the wolf and the deer, led his maniples forward in an impetuous attack.
The maniples of hastati would have closed with the Gauls at the run (impetus), pausing only momentarily to hurl their pila, roar their war cry (clamor), and draw their swords. The centurions and soldiers in the front would have surged ahead, aiming to batter down Gallic warriors with the bosses of their shields, force their way into the ranks and set to work with their cut-and-thrust swords. The soldiers in the rearmost ranks of the maniples would follow up more steadily in good order, drumming weapons against their shields, shouting encouragement to their comrades and perhaps lobbing pila over their heads and into the ranks of the enemy.
But the Senones resisted fiercely. They too were armed with pila-like missiles, which must have thinned the ranks of the attacking Romans, and their long swords could hack through shields and armour. The two sides were evenly matched in fury and prowess and the infantry action gradually waned. We may presume that Mus called up the principes to relieve or reinforce the hastati, but when they too failed to break the Senones, the consul looked to his cavalry to hasten victory. Riding from turma to turma he exhorted the mostly rich and aristocratic troopers: ‘Yours will be a double share of glory if victory comes first to the left wing and to the cavalry!’
The cavalry on the left wing would have moved forward to protect the flank of the advancing infantry, but until now, there was no all-out cavalry assault. Mus attached himself to the bravest turma (perhaps actually his mounted bodyguard) and led two charges against the Gallic horse. The first charge drove the Gauls back and the second scattered them, exposing the unshielded right flank and rear of their infantry, but the Romans were unable to exploit the opportunity. The war chariots of the Senones had been held in reserve behind the battle line. The sudden and unexpected counter-charge panicked both horses and riders, and the Roman cavalry fled in disorder as the clattering chariots pursued them. Mus was unable to halt their flight, and the fugitives appear to have swept past the flank of their own infantry. The charioteers broke off their pursuit and turned instead on the vulnerable infantry, driving into the intervals between maniples and ordines. Many of the antesignani, that is the hastati or principes in the leading battle line, were trampled down. The Gallic infantry took advantage of the chaos and attacked.
With the cavalry in flight and the leading battle line of infantry almost overrun, it seemed that the Roman left might collapse. If the left fell, Rullianus’ wing would surely also succumb and with it Rome’s hard won conquests in Italy. Decius Mus decided that the time had come for him to follow the example of his illustrious father: he would ride to his death as a devotus and through his own sacrifice bring about the destruction of the enemy. Livy has him utter: ‘Now I will offer up the legions of the enemy, to be slaughtered along with me, as victims to Tellus [Mother Earth] and the divine Manes [gods of the Underworld].’
Livy informs us that throughout the battle Mus kept the pontifex, Marcus Livius Denter, close. Such a senior state priest was necessary to lead a devotus through the correct ritual. That Mus had Denter by his side at all times suggests that his decision to perform devotio was not spontaneous. The consul’s heritage must have led to expectations that he too would perform devotio if the situation facing Rome became desperate and Sentinum was such an occasion. It is likely that he informed Rullianus of his intention to devote himself if his initial tactics failed. The legionaries and allies would have been told as well. If they were not prepared, they would most likely panic at the sight of the consul being cut down.
A spear sacred to Mars was laid upon the ground and Mus stood upon it. Denter helped the consul recite the terrible prayer of devotio, the same with which the original Decius Mus had devoted himself at Battle of the Veseris. It is possible that Livy or his sources invented this, but it seems likely that it derives from pontifical or other priestly records of religious formulae:
Janus, Jupiter, Father Mars, Quirinus, Bellona, Lares, divine Novensiles, divine Indigites, you gods in whose power are both we and the enemy, and you, divine Manes, I invoke and worship you, I beg and crave your favour, that you prosper the might and victory of the Roman people and visit on their enemies fear, shuddering and death. As I have pronounced these words on behalf of the Republic of the Roman people, and of the army and the legions and auxiliaries . . . I devote the legions and auxiliaries of the enemy, along with myself, to the divine Manes and Tellus.
The younger Mus added some grim imprecations to this vow of death:
I will drive before me fear and panic, blood and carnage. The wrath of the heavenly gods and the infernal gods will curse the standards, weapons and armour of the enemy, and in the same place as I die witness the destruction of the Gauls and Samnites!
Denter helped Mus don the ritualistic garb of the devotus. This was the cinctus Gabinius, a toga hitched in such a way that a man could ride a horse and wield a weapon. The consul was ready to meet his destiny, but first proclaimed Denter propraetor (he had been consul in 302 BC). Thus invested with imperium, Denter assumed command of the consular army.
Brandishing the spear of Mars, Mus spurred his way through the broken antesignani, charged into the ranks of the advancing Senones and impaled himself on their weapons. The death of a general, the focus of command and authority and leadership, usually triggered the collapse of an army, but the news of Mus’ glorious demise, transmitted by Denter, rallied the hard-pressed Roman infantry and they turned on their opponents with renewed vigour. According to Livy, Mus’ heroic death had the effect of instantly paralyzing the seemingly victorious Gauls:
From that moment the battle seemed scarce to depend on human efforts. The Romans, after losing a general – an occurrence that is wont to inspire terror – fled no longer, but sought to redeem the field. The Gauls, especially those in the press around the body of the consul, as though deprived of reason, were darting their javelins at random and without effect, while some were in a daze, and could neither fight nor run away.
The Senones’ reaction seems entirely fantastic but is it entirely fictitious? Is it merely the over-egged reconstruction of a patriotic Roman historian or does it have some basis in reality? Livy was keen to describe how the self-sacrifice of Mus brought on the aid of Tellus and Manes and the form that aid took, but were the Senones aware they had killed a devotus? It is possible that they did, and their reaction, although exaggerated, was one of shock and caused their advance to halt.