Antiochus III the Great: The Seleucid King Who Took on Rome

Antiochus III the Great, the Seleucid king, was a fascinating personality. He took Hannibal in his court, campaigned all the way to India, and even stood against Rome in a war that would seal the fate of the Seleucids. For a brief moment, it seemed as if he would be the one to stand up to Rome and reverse the course of his declining empire. However, history had other plans.

Antiochus was born in c. 240 BCE and became king at 19 years old. When he took over, he had some experience ruling over the eastern satrapies of the Seleucid Empire during the reign of his father, Seleucus II. Still, he was quite young and did not seem ready to govern an empire. Therefore, young Antiochus offered increased autonomy to his subjects. Sensing the young king’s weakness, Molon and Alexander, the satraps of Media and Persis, rose in rebellion, hoping to overthrow Antiochus. The Seleucid Empire faced an existential crisis as a series of separatist movements from Bactria to Babylon.

Antiochus did not lose time. In a war described in the 5th book of Polybius’ Histories Antiochus rushed to take back what was his. Even in the complete chaos of the war, Antiochus’ status as rightful king, meant something for the people. In the decisive battle between the armies of Molon and Antiochus near Babylon, Molon’s whole left-wing changed sides upon realizing that they were facing the king. Encircled and in fear of being taken prisoners, Molon and Alexander committed suicide. Antiochus handled his victory calmly and did not punish the cities that had cooperated with his enemies. He then attacked the independent Atropatene and ordered the assassination of Hermeias, a courtier who had been consistently undermining him.

The civil war was almost over, but there was still a dangerous pretender who had not been suppressed. Amid the chaos of war, Achaeus, a relative of Antiochus, had taken over Lydia. Antiochus did not move against Achaeus right away. Instead, he attacked the Ptolemies and took over Coele-Syria. After negotiating a truce with the Ptolemies, the Seleucid king attacked Achaeus and ended his rebellion. Antiochus was now the last man standing. He was the indisputable ruler of the Seleucid Empire.

Upon restoring order in the heart of his empire, Antiochus was ready to turn his eyes towards the east and reclaim the lands that his ancestor Seleucus I Nicator had conquered a century ago. But this wouldn’t be easy. Parthia, a new Persian kingdom, had grown to become a considerable threat, while Bactria in modern-day Afghanistan had gradually become independent since around 245 BCE.

Before launching his eastern campaign (Polybius, Histories 10.27-31), Antiochus decided to secure his northern border. So, in 212 BCE, he invaded Armenia. This war ended with a forced alliance between the two powers secured by the marriage of Antiochus’ sister, Antiochis, with the Armenian king. Antiochus was now ready to retake the east.

First, he moved against the Parthian king Arsaces II. With swift moves, Antiochus managed to enter Hecatompylus, the enemy’s capital, without facing serious resistance. He ordered his army to rest there and began planning his next moves. Seeing how easily Arsaces had abandoned his capital, he concluded that the Parthians had not enough resources to face him in direct battle. So, he decided to pursue the retreating Parthians before they could organize. However, the road towards Hyrcania, where the Parthian army was headed, was rough, mountainous, and filled with enemies. It took eight days for Antiochus’ army to cross Mount Labus and enter Hyrcania. After a series of confrontations, the Seleucids placed Sirynx, the regional capital, under siege and eventually broke through the enemy’s defense. After the fall of Syrinx, Arsaces II gave in to Antiochus’ demands and entered into a forced alliance with the Seleucids in 209 BCE. Parthia had been tamed. Now it was Bactria’s turn.

Bactria—an area situated in modern-day Afghanistan, north of the Hindu Kush region—was governed by a Greek kingdom, which had taken a separate course from the rest of the empire. Bactria was a true island of Hellenistic culture amid an ocean of local populations.

At the time of Antiochus’ campaign, Bactria was ruled by king Euthydemus. In a fierce confrontation with Euthydemus’ army (Polybius, Histories 10.48-49; 11.39), Antiochus lost his horse and a few of his teeth, thus becoming known for his bravery. The war, however, did not continue as the diplomatic abilities of Euthydemus led to peace in 206 BCE. The Bactrian king convinced Antiochus that a prolonged war could weaken the Greco-Bactrian forces and imperil the Greek presence in the area. As part of the treaty, Euthydemus gave all of his elephants and promised to become an ally of the Seleucids. In return, Antiochus recognized Euthydemus’ authority over the region.

The Seleucid army left Bactria and crossed the Hindu Kush into India. There Antiochus renewed his friendship with king Sophagasenus of the Mauryans, who offered him more elephants and promised to pay tribute (Polybius, Histories 11.39).

The eastern campaign was finally over. Antiochus had now earned the title “Megas” (Great) and had also established a network of powerful allies and tributary states.

Hannibal Joins Antiochus: The Romans Are Worried

Upon returning to Syria, the Seleucid king sought to strengthen his presence in the area. He took back control of Teos from the Attalids and seized Coele Syria from the Ptolemies. For the next decade, Antiochus fought against his neighbors, growing his influence in Thrace and Asia Minor.

At the same time, his legend in Rome was growing. The Romans heard of an eastern king who had subdued Asia and seized Coele Syria from the mighty Ptolemies. A strategic mastermind that no one could defeat. In the meantime, Hannibal Barca, the famed Carthaginian general who had brought fear in the heart of Rome, had also joined Antiochus’ court. By this time, both sides understood that full-scale war was inevitable.

In 192 BCE, the Aetolian League sent an embassy to Antiochus asking for his help to oust the Romans from Greece. Reportedly, Hannibal advised that fighting the Romans in Greece was unwise. He thought that the Seleucids should surprise the Romans and take the battle to Italy as he himself had previously done. He also directed Antiochus to rely on his own army and not on promises of Greek support, which were unreliable at best and empty at worst. Antiochus did not listen to the experienced general and, with an army of just 10,000 troops, traveled to Thessaly, where he made his headquarters for the winter.

The ancient sources agree that Antiochus neglected to make any serious preparations. Some authors even claim that Antiochus met a local girl and spent the winter without thinking of the ensuing war.

“… having fallen in love with a beautiful maiden, whiled away the time in celebrating his marriage to her, and held brilliant assemblies and festivals.​ By this behavior he not only ruined himself, body and mind, but also demoralized his army.”  Diodorus Siculus, The Library of History 29.2

The Seleucid Empire vs Rome

In the meantime, the Romans were vigorously preparing. Finally, in 191 BCE, the Roman statesman and general Manius Acilius Glabrio was sent to confront Antiochus. Realizing that he had no serious ally in the area and that his forces were not ready for a war, Antiochus decided to defend in the narrow passage of Thermopylae where the 300 Spartans had once stalled the mighty Persian army of Xerxes. But Antiochus was no Leonidas and the Roman legions were not like the Persian immortals. The Seleucids were crushed and Antiochus left for Asia.

As the Roman expeditionary forces now under Scipio Asiaticus, accompanied by his brother Scipio Africanus, entered Asia, they faced almost zero resistance. Evidently, Antiochus had decided not to defend the crucial city of Lysimachia and had asked its citizens to seek refuge further into Asia. “This was a foolish plan”, Diodorus Siculus would write later. Lysimachia was a strong fort capable of holding the gates of Asia, but now this large city was just handed over without a battle and in good condition. Upon entering the empty Lysimacheia, Scipio could not believe in his luck. And his luck did not end there.

In the decisive battle of Magnesia ad Sipylum in 190 BCE, the Roman general fielded an army of 30,000 against Antiochus’ 70,000. With the exception of a 16,000-man Macedonian phalanx, Antiochus’ army was, for the most part, poorly trained and incapable of taking on the disciplined Roman legions.

During the battle, the Romans quickly managed to take the center and outflank the Seleucid reserves. One of the reasons they managed to do that so easily was that the unstoppable scythed chariots of Antiochus had run amok, destroying the formation of his left-wing in an attempt to seek refuge from enemy missiles. As the left-wing crumbled, the center became exposed and Roman missiles caused Antiochus’ large Indian elephants to panic, inflicting further damage on their own lines.

Antiochus was completely unaware of the situation. The king, leading the right-wing, had successfully pushed his opposing Roman wing back to its camp. Returning to the battlefield, Antiochus was certain of his triumph. He must have expected to find his army chanting his name, but he couldn’t have been more wrong. What he encountered must have been terrifying. The massive Seleucid army, one of the largest armies assembled until then, was in shambles. Antiochus was essentially witnessing a glimpse of the Seleucid Empire’s end. The world of Alexanders’ successors was about to become the world of the Romans.

At the same time, the Roman fleet defeated the Seleucid navy under Hannibal’s command near Syde. Land and sea belonged to the Romans. Antiochus had no other choice but to retreat further into Asia. The Romans could not believe how easily they had won. This was a total defeat for Antiochus.

In 188 BCE, the treaty of Apamea was signed. Antiochus agreed to all the terms of the Romans:

“… the king must withdraw, in favour of the Romans, from Europe and from the territory​ on this side Taurus and the cities and nations included therein; he must surrender his elephants and warships, and pay in full the expenses incurred in the war, which were assessed at 5,000 Euboean talents; and he must deliver up Hannibal the Carthaginian, Thoas the Aetolian, and certain others, together with twenty hostages to be designated by the Romans. In his desire for peace Antiochus accepted all the conditions and brought the fighting to a close.” (Diodorus Siculus, Library of History 29.10) 

All the lands west of the Taurus would hence belong to the Romans who would give them to their loyal allies, the Attalids and Rhodes. Antiochus had promised to surrender Hannibal as part of the treaty, but knowing the Romans, the Carthaginian had already escaped safely to Crete.

Antiochus spent his last years trying to maintain and expand his weakened influence over the east. He was killed in Elam in 187 BCE, as he was pillaging the temple of Bel in an attempt to replenish his empty coffers.

Antiochus III the Great had managed to become the king who had, at the same time, both restored the glory of the Seleucid Empire and signed its doom. Against all odds, he had managed to fight against a series of civil wars, launch a campaign to India and back, conquer Coele Syria, Asia Minor, and Thrace, take Hannibal in his court, and worry the Romans. But in the end, when he fought against Rome, it became apparent that even he did not have the wit or the power to bring down the military machine that would dominate the ancient world for centuries to come.

Was Antiochus Great? 

Alexander the Great, Constantine the Great, Charles the Great (Charlemagne), Catherine the Great, and so on; we are used to talking about the ‘greats’ of history. Even though Antiochus III is today known as “the Great”, this is probably due to a poor translation of his official title. All Seleucid Kings had unique titles. There was Seleucus I Nicator (the Victorious), Antiochus I Soter (the Savior), Antiochus II Theos (the God), and so on. Antiochus III was known as Antiochus the Great, but his full title was Basileus Megas Antiochus (Βασιλεύς Μέγας Αντίοχος), which translates to King Great Antiochus or rather Great-King Antiochus. This means that Antiochus’ title was related to the Mesopotamian tradition, according to which the area’s supreme ruler was called the King of Kings, the King of Lords, or simply the Great-King. Persian rulers typically carried such titles though the Greeks avoided them. Antiochus was an exception to this rule and there was a good reason for that. After his eastern campaigns, he reigned over the vast lands that once were part of the great Persian Empire. As a result, fancy and prestigious eastern titles appeared entirely appropriate for his case.

But, what did Antiochus do, exactly, to deserve such a name? Antiochus lived at a time when the Seleucid Empire was a shadow of its former self. The dynasty’s founder, Seleucus I, ruled over a kingdom that had one leg in India and the other in Thrace. But almost six decades later, the empire was in disarray. Antiochus III reclaimed a great part of the empire and forged a series of alliances with powerful kingdoms. For a brief moment, he even challenged Roman rule, but in the end, he was not capable of defeating the Romans.

Under Antiochus, the Seleucids signed the humiliating treaty of Apamea (188 BCE) and were doomed to become a peripheral power that would eventually wither away. In many ways, Antiochus deserves some of the praise but was he “great”?  Well, if we suppose that this title is reserved for the greatest of conquerors only, then no.