The turning point of the battle occurred when the Scythed chariots led by Archelaus dived into Nicomedes army. According to Appian, the chariots caused wounds of such a hideous nature that they caused fear and confusion among Nicomede’s troops, “…cutting some of them in two, and tearing others to pieces.” So horrified was the army at the spectacle of men being cut in half while still breathing or their mangled bodies hanging in parts on the scythes that, “overcome rather by the hideousness of the spectacle than by the loss of the fight, fear took possession of their ranks”.”This gave Neoptolemus time to regroup and attack what was now the rear of Nicomedes’ army. Even though Archelaus and Neoptolemus now had the clear advantage, the battle did not end until Neoptolemus had lost most of entire army.
Asia Minor at this time was still very wealthy, and able to support armies of considerable magnitude. Whilst we have very precise figures from the ancient sources, these are by no means consistent. Exactly how many men were actually present must always be a matter of speculation. Appian reckons that the Romans mustered 120,000 men between them. Cassius put himself on the border of Bithynia and Galatia, whilst Aquillius moved into the most dangerous position, ready to intercept and defeat Mithridates along his line of march if, as expected, he took the initiative and invaded Bithynia. Oppius meanwhile was in Cappadocia positioning himself for an attack on the Pontic underbelly, perhaps considering a strike up the valley of the Iris at the Pontic capital of Amaseia.
Nicomedes was aiming for the same destination as Oppius, but by a different route. He had taken 50,000 foot and 6,000 cavalry, and was making his way up the valley of the River Amnias, through the highlands of Paphlagonia. From there, once over the Halys, a good road led through the fertile olive groves of the Pontic heartland, past Lake Stiphane (modern Ladik Gyul), and then there was a gentle descent to the Iris river valley. Here, all going well, Nicomedes would unite with Oppius, and the pair would swoop on Amaseia (possibly detouring slightly en route to plunder Sinope) and claim victory. Such, at least, seems to have been the plan. As Wellington was later to observe, it is a rare plan that survives contact with the enemy, and Mithridates was following a different agenda entirely.
His army was mustering at Chiliokomon, between the Iris and the Amnias. This army was supposedly between 150,000 and a quarter of a million strong, though it is quite likely that the Roman historians greatly magnified the numbers so as to make their subsequent performance look better. For generals, Mithridates had chosen two brothers, Neoptolemus and Archelaus, whilst Arcathias, the son of one of Mithridates’ concubines, was in charge of 10,000 horse from Armenia. When news reached the Pontic camp that Nicomedes was on the move, Arcathias was sent to determine whether this was a full-scale invasion or a feint. Neoptolemus and Archelaus accompanied him with light infantry and some chariots, but the overall impression is of a reconnaissance in force rather than a full-scale counter-invasion.
The Pontic chariots – Mithridates is said to have had six hundred of these – were something of a throwback. As a platform for missile troops the chariot had over the centuries been replaced by horsemen, both because selective breeding had made horses steadily larger and more easily able to bear riders in combat, and because there were few areas in Asia Minor that lent themselves readily to chariot warfare. Yet Mithridates had chosen not merely chariots, but scythed chariots – heavy chariots with huge curved blades affixed to the wheels. These chariots could be devastating against enemies inexperienced with coping with them, assuming that somewhere suitable could be found for their deployment.
Such a place was the wide flat plain bordering the River Amnias, into which Nicomedes obligingly led his army, confident that his greatly-superior numbers and more heavily-armoured infantry would force the enemy to give ground. To avoid that very eventuality, the Pontic generals sent a force ahead to seize a rocky outcrop between the two armies which would make an excellent defensive bastion. Nicomedes anticipated the move and deployed his own forces so rapidly that the Pontic advance force was in danger of being enveloped. Neoptolemus advanced to their rescue, with the cavalry of Arcathius keeping the enemy off his flanks. Meanwhile, Archelaus and his highly-mobile light infantry scooted around the edge of the enemy army to distract them with a flank attack should the need arise, as it probably would, given the greater strength and numbers of the Bithynians. Accordingly, once the Pontic centre started to crumble under the mauling its troops were receiving, Archelaus launched his attack to distract the enemy, whilst Neoptolemus’ men fell back and reorganized themselves.
Having established that Pontus had superiority in cavalry, Arcathius looped back to try to get behind the enemy lines, which were in some disarray after fighting on two different fronts. It was time for the scythed chariots. These, as Appian relates were driven at high speed into the Bithynian ranks. Some men were sliced in two within an eyeblink, others were practically shredded. The army of Nicomedes saw men in two halves, yet still alive and breathing, others sliced to pieces, their mangled organs still hanging from the scythes. They had by no means lost the battle, yet the sight was so hideous that they were overcome with confusion, and fear disordered their ranks.
The Pontic troops pressed their advantage. Archelaus and Neoptolemus returned to the attack, each from a different angle. This was disconcerting enough for the Bithynian phalangites, since the entire principle of the phalanx was that the entire army should fight pointing in the same direction. But the problem became immeasurably worse when Arcathius turned up again and hit them in the rear with his cavalry. Though now at a disadvantage, the Bithynians fought on grimly. Yet in the back of their minds there must have been the knowledge that if this was only the advance guard of the Pontic army, the Bithynians were surely doomed once the main Pontic force turned up, as it might do at any minute. Eventually, with his men dying in large numbers, and the battle turning steadily in favour of his enemies, Nicomedes decided that it was time to cut his losses, leave his army to its fate, and get himself off the plain whilst he still had the chance.
The departure of their king was the signal for the Bithynian army to call it a day. Fighting to the death was not a local tradition, and dying for one’s king became less appealing when that same king was a rapidly diminishing dot heading for safety on the horizon.
For Pontus this was a highly rewarding battle in every sense. It was certainly won through the skill of the commanders who had used the mobility of their troops to maximum advantage, and had played the trump card of the scythe chariots at the best possible moment. Yet this would not have been possible without the discipline of soldiers who could manoeuvre quickly in discrete units, and retain their formation in the face of enemies who were more numerous and better-equipped. Almost certainly, the experience gained in fighting Scythians was now paying dividends – this was the performance of a veteran army, confident in its ability and that of its commanders, even against uncomfortable odds. Not only was Pontic morale greatly boosted (since a major enemy army had been knocked out without even engaging the main Pontic force) but Pontic coffers received a commensurate boost, as Nicomedes’ camp was captured and his war-chest along with it.
Mithridates made the most of the propaganda value of his victory, explaining to the remnants of the Bithynian army now in his power that his quarrel was with Rome rather than themselves. He not only allowed anyone who wanted to go home to do so, but even gave each funds and provisions for the journey. But not everyone would have wanted to go home. The loyalty of Nicomedes’ mercenaries was to Nicomedes’ pay-chest, and if that was under Pontic control, then so were the mercenaries. Consequently, it is probable that the manpower of the Pontic forces actually increased despite the casualties incurred in the battle.
