It isn’t easy to write about Ausculum/Asklo without mentioning the reason why this battle was fought without looking at the big picture.
A way to do that is to start from the high point of the earlier years’ campaign on Roma (280) and go from there.

A- A prelude to the battle itself. (Note that the preparation for the battle is in part B- Skip to that part if you want to read only about the battle)

Pyrrhos’ army was camped in Prainestos (Praeneste). His scouts reached even up to 4 miles from Roma itself. That would be as far as he would ever get though. The news he had been expecting reached him and weren’t good. Etruscans had just made peace with the Romani and as such the combined assault on the city or Roma was no longer feasible or possible. Consul Tiberius Coruncanius and his legions had reached Roma from Etruria. The backup army (which Roma created for its defense) under dictator Gnaius Domitius Calvus were ready to defend its walls. The other consul, Laevinus, and his strong army approached to help Roma, threatening Pyrrhos’ line of retreat and supplies.
Pyrrhos now faced an impossible task. Attacking Roma, while surrounded as he was by both Consuls and risk all of his army in this way, would be his undoing. Truth be told, an attempt against Roma at this point wouldn’t be successful. He opted to wait instead, in the off chance that either consular army would offer him a strategic opportunity to deliver a decisive blow, so he could then turn his attention at the other army. During this time, Pyrrhos must have made some diplomatic advances towards Roma in hopes of securing peace. The consuls though, didn’t offer him that chance. Instead of moving, they remained in place, relinquishing the initiative on Pyrrhos’ troops. It isn’t easily understood why, as the combined consular armies were much stronger than Pyrrhos’ troops and they could end Pyrrhos’ campaign right there and then. They didn’t though. It seems that the “Leukanian oxen” (as Romans called the elephants) did strike terror in the hearts of their men, whether or not they cared to admit it.
Pyrrhos’ position though was far from certain. Winter was closing in and the opportunity for a quick and decisive victory was vanishing. Standing on and attempting to lay siege was out of the question. So, trapped between two consular armies, in a desolate and enemy countryside, forced to scatter his troops so that he could locate more and more food for army, making himself more vulnerable by the day. His troops weren’t immune to infighting over scraps of food, if the chance presented itself, as it was completely heterogeneous. A motley crew of Roma-hating tribes along his Epeirotes and Tarantines. Faced with the dissolution of his army he consciously made the decision to retreat.
The people residing in those areas begged him to change his mind, fully aware of Roma’s retaliation. Pyrrhos, however, was a soldier first and foremost and as such he couldn’t allow mercy for the people who sought protection to stand in the way of general strategy. So, he was candid enough to tell them that he would leave as he couldn’t support his troops there. The retreat was orderly, as the Romani Consuls probably allowed him to depart, rather than assault him, otherwise they would have done so already. The troop movement was not easy, not with all the loot and prisoners the troops carried along. The Elephants were in the front and everyone else followed. Consul Tiberius Coruncanius tried to harass Pyrrhos as he departed but was ultimately unsuccessful. Zonaras mentions that Consul Laevinus arranged his army for battle, but didn’t attack. Pyrrhos tried to calculate the size of the enemy troops by having them clang on their shields and armor (after his troops did likewise). He considered them superior to his own and thus didn’t attack, justifying his actions by mentioning that the oracle didn’t favor fighting that day. Some historians say that it was here that he mentioned that “Roman legions are like the heads of Lernaia Hydra, cut one, nine more appear”, while most attribute this to Kinneas his close advisor and philosopher. Pyrrhos withdrew without casualties.
The rest of the winter was spent uneventfully. Appian suggests that Pyrrhos sent his troops to winter among his friendly cities in Campania, while modern historians as Niese consider that his troops must have remained near Taras as Campania was a hostile ground. Roman troops were sent to pass the winter at Ferrentinum, but by order of the Senate, the troops which lost at Heraclea (in what they called back then the battle of Siris river) would pass their winter in their tents up in the mountains, exposed to the elements of nature and forced to find their food with constant clashes. Frontinus mentions that Senate demoted the eqvestrians that Pyrrhos took as prisoners to foot soldiers, aka simple legionnaires and the legionnaires were demoted to missile troops (probably ascensi).
Pyrrhos tried to make peace with Roma in the following winter. His goal wasn’t the destruction of Roma, especially so after he witnessed the Romani war machine, but the formulation of a peace which would allow him to create a state in Southern Italy. If Roma was defeated, then the Taras’ civilians would have no longer need of his services and he would be kicked out, much like what happened in Syracuse after he defeated the Karthadastim there. Pyrrhos was aware of this, or more importantly, Kineas was. A strong Roma encroaching on its borders would keep Taras and all of South Italy firmly entrenched in the Epeirotes hands.
A lot of anecdotes have been passed down to us on the verbal interplay which took place between Fabricius and Pyrrhos and the attempts of the latter to win Fabricius over. His stance of absolute belief in Roma and its laws and blatant disregard of money (or as Perikles himself put it when accused of corruption “ΧΡΗΜΑΤΩΝ ΚΡΕΙΤΤΩΝ” or better than money) must be correct, if his overall life is anything to go by. It was men like him that enabled Roma to rise. However, the biggest majority of stories about them is merely Romani propaganda, an ipso facto attempt to justify Roma’s conquests. Pyrrhos’ offer to allow the men to return to Roma for the celebration of <<Jupernalia?>>. They all returned, but no peace treaty was signed.
Pyrrhos knew that if he was to get what he wanted he would have to fight for it. So, in the spring of 279 BCE he gathered his troops and set out for Roma again. A lot of speculation exists on the size of troops involved, but the size of 40.000 for both is considered the most agreed upon, especially if the Logistics of moving an army in South Italy is involved. Others, consider Dionysus and his account of 80.000 men for each as more accurate. Pyrrhos, was acutely aware of one thing. He could easily get cut off. After having been almost surrounded in the previous year, when he crossed Campania and reached Anagnia and Praeneste/Prainestom, he devised a different plan this time around, He would clear out Apulia, where he could count on Dauni and Peuketii rebelling and then he would invade Campania, creating in this way a war front against Roma and having his flanks completely secure of enemy forces. He would not be caught into a vise again.
According to that plan, Pyrrhos invaded Apulia, conquered many of its cities, some by force, some not, (as Niebuhr suggests) and after attacking Venusia reached Ausculum/Asklo. There he found the Romani waiting for him, commanded by Consuls Publius Sulpicius Saverrio and Publius Decius Mus.

B Preparations for battle.

The two armies stood in the opposite sides of river Aufidus (according to Niebuhr and Beloch). The standoff lasted for days and they didn’t attempt any war action during that time. The presence in the camp of Publius Decius Mus gave rise to the rumor that Decius Mus, inline with his ancestors sacrifice, he would seek death by charging alone on his horse on the spears of the Epeirotes. In that way he would offer his life as sacrifice to the gods below. Historical tradition reports that in earlier times in a war versus the Latins, the two Roman consuls, one of which was Publius Decius Mus ancestor of the one arranged for battle in Ausculum/Asklo, had camped in Capua. In that night, both the Consuls saw the same dream. A very tall man in size an stature who told then that whoever seeks to die among the enemy lines and will sacrifice himself, will bring victory to his army. After discussing about it, the two consuls decided that the one whose legions would crack under pressure first would do what the dream commanded. Decius ones were the first to crumble. Decius then, after praying to the gods, dressed himself in sacred attire, rode his horse and rushed all alone against the ehemy lines. His weird appearance created confusion in his enemies. Latin troops didn’t know what to make of him, so they let him into their holdings. Romani troops gained their strength back and attacked, winning the day.
Another Publius Decius Mus, consul himelf for that year 10 years later, son of the Hero consul, would lead his Roman legions along with his co-consul against the Samnites, Etruscans and other enemies of Roma. In the battle which ensued, Romani found themselves in a very precarious position, in danger of being defeated. It appears that again Publius Decius Mus wore a similar attire as his father, and he too felt on the spears of the enemy troops, inspiring the Romani to fight on and gain victory.
As could be expected, rumor was ripe in the Epeirote camp that the same thing would happen. It must be understood that most of the troops of Pyrrhos were herdsmen from the mountains of Pindos and not strangers to mysticism or superstition. In fact, superstition was more than prevalent in their daily lives than rational thinking. Facing another Publius Decius Mus and knowing the story that was associated with them, they assumed that the third Publius Decius Mus would do the same, and in fact he was said to be ready to do the same thing. However peculiar this may sound today, more than one battles in the ancient times were decided by the morale or lack thereof rather than just force of arms. Word spread among the troops that the Romani would surely win, if Publius Decius Mus sacrificed himself, so much so that it stands to reason that it could be considered a Romani ploy to take advantage of simple herdsmen such as Epeirotes were. Pyrrhos knew he had to take some action or the campaign to save Taras and forge a kingdom in Southern Italy would end there and then. So he gathered up his troops and explained to them that they shouldn’t lose heart nor their courage by paying any attention to such imaginary fears. A man cannot defeat an army by dying nor can anyone become stronger than men by sorcery and witchcraft. He tried to talk some common sense into them, inspire and encourage them. He described the attire that Publius Decius Mus would be wearing if he was going to make that sacrifice and ordered them not to kill him, but capture him alive. He also sent word to Publius Decius Mus that he shouldn’t attempt such a feat or he would be captured and treated very harshly, not as a prisoner of war. Romani consuls answered that they had no need for using any means other than force of arms to win the day. Cicero, however, writes that Publius Decius Mus did die in the battle of Asklo/Ausculum. If so, his death didn’t have much of an effect.
A more pressing problem for the Romani was the need to neutralize the 19 war elephants of Pyrrhos. Their secret weapon was 300 antielephant chariots in which long iron rods were placed. Moving spears were also attached on them as well as iron scythes on the edges of the chariots. Charioteers’ work would be to shoot flaming missiles at the elephants and hurt them with the iron spears. The chariots would be placed on the spot in which the assault of the Elephants would take place, wherever that might be. Romani were sure that those chariots would bring them victory, as the analogy of 20 chariots to an elephant as well as the volatile nature of the beasts, which would start stampeding on their own troops would cause such a confusion that instead of victory, they would be the cause of Pyrrhos’ ruin.
Pyrrhos himself, formulated a different strategy than that used in the battle of Heraclea/Siris river. He saw the manipular way of fighting that Romani took from Samnites and evolved to their own and realized its advantages. They were very agile and could fight on any terrain, whereas his own pike phalanxes were slow moving and could only operate in a flat ground. So he interjected among his different pike phalanxes manipular fighting units, aka his Italic allies. Where that wasn’t possible, greek mercs and hoplites were used instead. Not as good in that particular way of fighting, but surely better than pike phalanxes. He also sent all his sphendonetai and toxotai to escort the Elephants and fire at the anti elephant chariots.
According to Dionysus (XX,1) whose description seems to be the more accurate, the army of Pyrrhos had the following order of Battle In the right wing the Epeirote phalanx was placed and alongside it the Italian mercs of the Tarantines, Ambrakian phalanx, Tarentines Leukaspides (whiteshields), Bretii and Leukanoi. Center was held by the Thesprotoi and Chaones and mercs from Aitolia, Akarnania and Athamania. Left wing was given to the Samnites. Right wing was also supported by Samnites, Thessalians and Brutii hippeis and Tarantine merc hippeis, whereas the left wing was supported by Ambrakian, Leukanoi and Tarantine hippeis and Akarnanian merc hippeis. On their rear were the elephants and missile troops. Romani left wing opposing Epeirote right wing was Romani cavalry, allies, first legion, allies and third legion. Center was held by allies and Fourth legion, and on the right wing facing the Epeirote left were allies, second legion and on the extreme right Roman cavalry with allied horsemen. On the rear of roman battleline were the 300 antielephant chariots along with skirmishers.
Using that battleline and those new tactics the two opposing armies clashed, sometime in the late summer of 279 BCE at Ausculum/Asklo of Apulia, present day Ascoli di Satriano.