A few weeks ago I was distracting myself by chatting about the Battle of Magnesia with Michael Park, a very thoughtful lover of ancient history. This battle was a shocking upset where the Seleukid king and and army raised from his whole kingdom were scattered by a small army from Rome and Pergamon which had not seemed very eager for the fight. The longest surviving accounts are by Livy (written about 150 years after the fact) and Appian of Alexandria (about 300 years later) both of whom had access to contemporary sources. This campaign is interesting to me because Antiochus’ enemies trotted out some 300-year-old tropes from the Persian wars to depict him as an Asiatic despot seeking to enslave Europe with his countless but feckless soldiers. However, they were limited by the fact that Antiochus and his Friends paid people to tell their story in fashionable Greek, so they could not claim that Antiochus had hundreds of thousands of soldiers or wore foreign clothing or was too cowardly to go into battle himself. If they went too far, people who had heard other versions after dinner or read them in a library would cry foul.

In this battle the fighting began on the wings, and each side won on its right: Antiochus and his Friends drove a legion back to its camp with the first charge, while panic broke out on his left wing and Eumenes of Pergamon found himself in control of the field there. The infantry on both sides had not yet engaged: perhaps Antiochus was nervous of the stories that while thyreophoroi were normally no danger to a Macedonian phalanx, the Roman ones had a way of getting into the small gaps which emerged if a phalanx tried to move too quickly or crossed rough ground. Livy gives us his version of what happened next:

The auxiliaries, posted between the cavalry and the phalanx, being thrown into confusion, the terror spread even to the centre. Here the ranks were broken, and by the flying soldiers rushing in between them, the use of their long spears, called by the Macedonians sarissas, was hindered. The Roman legions advanced and discharged their javelins among them in disorder. Even the elephants, standing in the way, did not deter the Roman soldiers, who had learned by experience in the African wars, both to evade the onset of the animal, and, getting at one side of it, either to ply it with darts, or, if they could come near enough, to wound its sinews with their swords. The front of the centre was now almost crushed, and the reserve, being surrounded, was attacked on the rear, when the Romans perceived their troops in another quarter flying, and heard shouts of dismay almost close to their camp.

Livy 37.42.3-6 c/o the Perseus Project

Appian has a different take:

The Macedonian phalanx, which had been stationed between the two bodies of horse in a narrow space in the form of a square, when denuded of cavalry on either side, had opened to receive the light-armed troops, who had been skirmishing in front, and closed again. Thus crowded together, Domitius easily enclosed them with his numerous light cavalry. Having no opportunity to charge or even to deploy their dense mass, they began to suffer severely; and they were indignant that military experience availed them nothing, exposed as they were on all sides to the weapons of the enemy. Nevertheless, they presented their thick-set pikes on all four sides.

They challenged the Romans to close combat and preserved at all times the appearance of being about to charge. Yet they did not advance, because they were foot-soldiers and heavily armed, and saw that the enemy were mounted. Most of all they feared to relax their close formation lest they might not readily bring it together again.

The Romans did not come to close quarters nor approach them because they feared the discipline, the solidity, and the desperation of this veteran corps; but circled around them and assailed them with javelins and arrows, none of which missed their mark in the dense mass, who could neither turn the missiles aside nor dodge them.

After suffering severely in this way they yielded to necessity and fell back step by step, but with a bold front, in perfect order and still formidable to the Romans. The latter kept their distance and continued to circle around and wound them, until the elephants inside the Macedonian phalanx became excited and unmanageable. Then the phalanx broke into disorderly flight.

(Appian 7.35 c/o Livius.org)

Now, it is traditionally said that both Appian and Livy are just summarizing Polybius, who was born about the same time as the battle and liked his military details. I doubt that, but I have not read the arguments behind that tradition. But here we can see how Livy has cut something out of his sources and tried to hide it. He leaves out the period when the phalanx was holding its own and challenging the Romans to “come and get some!” and the Romans were standing back. He leaves out Appian’s words describing the mortal terror which soldiers confronting the Macedonians felt (the verb δείδω and the adverb ἐπιφοβως). He also leaves out that most of the troops “assailing [the Macedonian phalanx] with javelins and arrows” were foreign cavalry and light-armed troops. Instead of talking about this phase, he moves directly to the end of the fight when the phalanx finally did begin to break up and the Romans began to kill people with swords and do other things that manly Roman soldiers were supposed to do. Appian is hardly a partisan of Antiochus, who he calls “generally fickle and light-minded” (6.28), but in his story of this battle he records some things which were favourable to him and his army which Livy did not want to repeat. (Similarly, none of the sources on the battle of Cunaxa is really ‘pro-Artaxerxes,’ but some of the alternative sources let us guess how Xenophon’s hatred of Tissaphernes and love of Cyrus has probably distorted his story).

An old legal maxim has it that suppressio veri suggestio falsi, to hide the truth is to spread a falsehood. Many ancient writers trained in rhetoric were masters of this, because it works so very well. Greek and Roman writers were not experts in source criticism or archival research, but some of them were very good at misleading careless readers.

Edit 2016-12-01: There is now a response to this post by Aaron B at Prufrockian Gleanings: Truth, Lies, Sources (and Videotape)

Edit 2018-07-28: Sarah C. Melville, “Win, Lose, or Draw? Claiming Victory in Battle”
Published In: Hans Neumann et al., ed., Krieg und Frieden in Alten Vorderasien, AOAT 401 (Ugarit-Verlag: Münster, 2014) pp. 517-537 argues that royal inscriptions followed the same general rule of ignoring or glossing inconvenient facts not inventing their own facts.