Or, Caesar’s and his Roman legions vs Alexander and his Macedonians.
Through a timey-wimey ball two of the greatest commanders of antiquity meet. The battleground is a flat plain in the Po Valley. The topography offers neither side an obvious advantage - their is no scope for ambushes, for example.
Alexander, naturally, is on the attack moving south towards Rome. Caesar and his legions move to intercept, meeting the Macedonians. Alexander knows he must brush aside these upstart Latins in order to conquer Rome and ensure Macedonian hegemony forever. Caesar knows his city faces the greatest threat since Hannibal and his legions are Rome’s last hope for keeping Alexander from the gates.
Caesar’s forces are those he had at the the Battle of the Sabis - 42,000 men. 8 post-Marian legions with their cavalry plus auxiliaries, fiercely loyal to their commander and Rome herself. Caesar’s legions are centuries ahead of Alexander’s forces and have cut their teeth fighting the Gauls. The system will go on to conquer Europe and the Mediterranean. Caesar is slightly outnumbered by Alexander’s forces and has as his deputies Mark Anthony and Titus Labienus.
Alexander has the force he first crushed the Persians with - 31,000 pikemen, 9,000 light peltast skirmishers, 7,000 cavalry, including the famed Companions. Alexander will ride with them at the front in his characteristic risky but inspiring style. His army will go on to crush the Persian Empire and march into distant India. Alexander is a tactical genius without match and has as his deputies Parmenion and Ptolemy.
Will Alexander’s genius allow him to take Rome and add Italia and Magna Graecia to his empire, realising his lifelong dream of panhellinism? Or will Rome’s most famous son stand as a reliable bulwark and be granted a triumphal procession for stopping the impossible invasion?
Poll inbound on how you think this battle would go if Caesar’s legions ever met Alexander’s phalanxes.
Phyrrhus was supposedly a “second Alexander” and had access to vaguely similar forces. He faced superior Roman numbers (though these were pre-Marian reforms) and generally won, though famously was unable to make up his losses or win the diplomatic war for allies, and so lost the war.
But that’s probably as close to a “natural experiment” as can be found for the scenario in the OP, so I’d say: Alexander wins the battle, but finds as Phyrrhus and Hannibal did that just defeating Roman armies doesn’t actually put much of a dent in Roman ability or willingness to keep fighting.
(Alexander also had the disadvantage that his strategy of leading calvery charges left him vulnerable to catching the wrong end of the pilum and thus losing the battle more or less by mischance. The romans would keep fighting without Caeser, but I doubt the Greeks would pack it in and go home without Alex.)
I disagree. The flat plain you postulate is advantageous to the phalanx. On an open field, Alexander should win decisively against Caesar. Caesar, however, will know this and will use his superior mobility to force the battle into a location that isn’t a flat plain.
Polybius writes on the very topic of the phalanx vs the maniple.
There’s also the argument that Alex would have more of an advantage in hilly terrain; the hoplon was created in the mountain passes of Greece for a reason. The phalanx formation is more easily flanked on flat terrain. AtG also stomped through Anatolia which is mountain after mountain.
I somehow suspect Alexander was plenty familiar with how best to deploy phalangites in most any terrain. Anyways, Polybius writes from pretty close historical proximity to the conflicts between Rome and the Alexandrian successor states, so his take on the subject is worth noting.
Alexander. The Cavalry, which the Romans were never good against, making all the difference. Alexander is better than Pyrrhus and has a more diverse combined-arms force. Agrianians, Cretans, Thessalians. The Romans were flat-track bullies, no good against a decent force. It’s Cannae all over again.
Hannibal failed because he couldn’t take Rome. Alexander’s biggest strength was taking cities. Hallicarnassus, Gaza, Tyre, Thebes, the Rock of Aornos.
When we had our little ‘greatest military leaders’ game ( where not incidentally Alexander edged Caesar ), I argued that I’d probably take JC over Alex for two reasons:
1.) JC was more mentally stable. Julius was a self-aggrandizing asshole megalomaniac, sure. But he was more of a Machiavellian type and rather less prone to slaughtering his own officers in a drunken rage.
2.) Alex was a bit more impetuous. Not only did he lead from the front line, nearly dieing on a few occasions, but he also repeatedly plunged himself into more strategic difficulties. Julius took chances, but I’m guessing he would never have marched through an uncharted desert the way Alex did and I think he would be more careful measuring himself against novel foes. Which cuts both ways at times - JC may not have conquered the tottering Persian state as quickly and completely either. However at the end of the day Alex was a wunderkind whose sheer ability ( and the occasional dollop of luck ) kept saving his ass from his own adventures, until it didn’t.
That said, given the OP’s scenario I’d be inclined to bet on Alex if he doesn’t croak during the fighting. He would have had an superiority in cavalry, which together with his light infantry could screen his own flanks and threaten JC’s, meanwhile those heavy Macedonian phalanxes would have been a terror in a face to face slugging match on even ground. Dunno that it would be easy, but I’d give him the edge in that particular tactical situation.
Caesar was the beneficiary of centuries of incremental improvements in military technology, and logistical, strategic and tactical thinking since Alexander’s time, not to mention knowing all about the innovations of Alexander himself, and the near certainty that the Roman legions were far better disciplined than Alexander’s forces. The legions had experience fighting all sorts of enemies. Alexander could win against the Persians and others because of his innovative tactical and strategic thinking against a traditionalist enemy. By Caesar’s time, Alexander’s innovations (and those of the earlier Greeks, upon whom Alexander built) were all old hat, and thoroughly assimilated and superseded.
First I don’t buy for one second that the Roman troops were substantially more disciplined than the Macedonian heavy infantry. Greek phalangites were nothing if not extremely disciplined, it was the key to their success. Particularly the Macedonian version, who were essentially the Swiss pikemen of their time with the long sarissa.
Nor do I think the incremental military innovations and tactical thinking amounted to much in context. That is to say I have no doubt that the Roman army was a more flexible and formidable force than the Macedonian army in general. But stick them out on an open level plain, ignore any context of a wider war where logistics et al come in to play and most of those advantages melt away. The OP’s scenario plays exactly to the phalanx’s strengths. In a face to face brawl with no natural features to take advantage of and neither a numerical superiority nor much of a mobility one, nor substantially superior generalship, the Romans will have a hard time flanking the Macedonians. And if they can’t flank them, they may well end up getting mauled.
I wouldn’t say it is a foregone conclusion, but I’d hedge my bets and take Alexander over a coin flip. If we’re talking about an extended war, I’d reverse that - the Roman system was just way too effective at spitting fresh armies compared to the Hellenes and legions were a far more flexible tactical unit than the phalanx under any condition other than the exact one set forth by the OP.
Keep in mind that Alexander’s phalangites were not the same thing as classical Greek hoplites. Smaller shields, small swords, much less armor, much bigger stick. (The dory spear was about 8 feet long, the sarissa 15-22 feet or so.)
After considerable cogitation and some re-reading, I am inclined to agree with Gorsnak.
While the phalanx could handle differences in elevation, the key is “unbroken” terrain. Anything – like trees, ditches, or boulders – that disturbs the tightly massed phalanx puts it at risk. On suitable terrain, however, the massed spears are famously terrifying – even the Romans hesitated to take on a Macedonian-style phalanx in a straight-up fight. The fighting power of the phalanx is one reason Alexander conquered the “known world.”
And Caesar would have simply refused to go in there head-to-head. He would have drawn the Macedonians into terrain inhospitable to the phalanx, or ambushed their camp at night, or anything but getting run over by that meatgrinder.
An individual legionary, however, is superior to a phalangite in equipment and probably flexibility of training. The Roman shield was much better than those carried in the phalanx, and the gladius would be somewhat better than the kopis.
If the requirement is that the Romans have to engage Alexander’s phalanx in frontal combat, well, they lose. But historically they avoided playing to the phalanx’s strength, to every extent possible.
I’ll add that I don’t see it being close; no matter who wins, they’ll win big. If the phalanx keeps together and hits the center mass of the (hypotheically stupid enough to take them on) Romans, they’ll bulldoze over them, and there won’t be many losses on the Greek side. But if the Romans get live legionaries inside the formation, they’ll chew up the phalangites very one-sidedly.
edited to add: The thrown pilum should give the legionaries back some of the range-of-engagement advantage the sarissas give the Macedonians.
Romans vs. Macedonians: Round 1 ( well, excluding Aous, a Roman victory in a skirmish centered mostly on positioning ) and Round 2 ( well, excluding Callinicus, a minor Macedonian victory in which only light infantry and cavalry played any significant role ).
The Spartan hoplites were a lot more primitive and limited then Alexander’s more mixed military. Not much in the way of calvary, missile or skirmishers. And they had a pretty mixed record against the more advanced troops of later antiquity.
And Leonides reputation is more for bravery then any particular skill at strategy (indeed, his main claim to fame is loosing a battle because he held a mountain pass but the troops he sent to hold an alternative route around the other way, which seems rather a blunder). So I think the Romans would make pretty short work of the Spartans.
But then, Caeser and the Roman’s liked winning battles, and the Spartans liked dying bravely in them, so I guess really everyone wins.