After four years of uneasy relations with the Romans, the Hellenistic ruler King Antiochus III finally disturbed their patience in 192 BC. He set sail from Asia Minor with a relatively small force of 10,000 men and landed in Greece, seizing control of several cities. Rome had been suspicious of the Seleucid king — now they knew war was inevitable.
192 BC: the Romano-Seleucid War erupts
In this act Antiochus crossed the line of no return, for the Roman Republic of the 2nd century BC viewed themselves as the new champions of Greek liberty in the Aegean. Antiochus’ invasion should have seemed a daunting prospect. Not only was his empire massive, but Antiochus’ previous military successes had been so formidable that he was already being hailed by some as the next great Greek general: the next Alexander.
Everything suggested that this war would be one of the hardest Rome had ever fought. Rome gathered its armies and prepared for war. Yet what followed would surprise even the Romans.
The Roman Battle of Thermopylae
Antiochus, seeing his supposed Greek support abandoning him to the advancing Romans, took a stand at Thermopylae. Thermopylae lies along the major north-south land route along the east coast of the Balkans and in the ancient world was the site of a narrow coastal passage. It had previously been the location of a prominent battle in 480 BC during the Greco-Persian Wars. Antiochus had been greatly outnumbered by the Roman coalition. The battle saw him suffer a crushing defeat.
Antiochus hastily retreated to Asia Minor. His campaigning in Greece had quickly turned into a catastrophe. In the process he lost face among many of his subjects: his expedition had proved reckless and ill-prepared. Yet Antiochus remained undeterred. It was a personal blow, but Antiochus’ failure in Greece was only a minor setback. His lands in Thrace and around the Hellespont, the doorway to Europe, remained firmly in Seleucid control.
Quickly strengthening, Antiochus’ forces once again crossed the Hellespont and entrenched themselves inside the city of Lysimacheia, their most formidable stronghold in Europe. On arrival, Antiochus ordered his men to gather supplies, sharpen the fortifications and prepare to weather the coming storm; the Roman armies were on their way. In Thrace, Antiochus’ men aimed to make up for their king’s failure in Thessaly. Fate, however, had other ideas.
Problems at sea
Sadly for Antiochus, things would once again not go according to plan. Not all the fighting was currently happening on land. At sea, thanks mainly to their alliance with Rhodes, one of the greatest maritime powers of the time, Rome continued to defy expectations.
Following two crushing victories over their opponents, including one against the Carthaginian commander Hannibal, the Romans wrestled control of the Mediterranean. This was a crushing blow for Antiochus and his European ambitions and its effect were significant.
Said to have panicked on hearing of his navy’s defeats, Appian recalls Antiochus’ next blunder:
Everything unnerved him, and the deity took away his reasoning powers, so that he abandoned the Chersoneses without cause […] leaving all these sinews of war in good condition for the enemy.
Appian, Syrian Wars, 6.28
Antiochus, distressed by his recent defeats, abandoned his final holdings in Europe. Lysimacheia, a city he had re-built from ruin into one of the most formidable fortresses in Europe, was simply left without a fight. The Romans could not believe their luck. Yet the war was still far from over.
How could Rome trust such Antiochus, who had already proved his expansionist desires, to refrain from conducting a more formidable campaign against them in the future? They refused to allow him to remain in command of a powerful kingdom on Europe’s doorstep.
Crossing the divide
Rome decided on a radical plan of action, agreeing for the first time in their history to send an army across the Hellespont into Asia. They aimed to confront Antiochus in his own territory and remove the threat he posed indefinitely. Under the overall command of the consul Lucius Scipio, seconded by his famed older brother Scipio ‘Africanus’, this army set off to become the first Roman army in Asia.
They crossed the Hellespont completely unhindered. Within six years of his crossing into Europe, Antiochus found himself back at step one. His expeditionary force into Greece had been routed, his fleets had been severely weakened, and his well-stocked fortifications in Thrace had fallen uncontested into the hands of his enemy. From now on, Rome would be the invaders.