Roman–Seleucid war
The Roman–Seleucid war, also called the Aetolian war, Antiochene war, Syrian war, and Syrian-Aetolian war was a military conflict between two coalitions, one led by the Roman Republic and the other led by the Seleucid king Antiochus III. The fighting took place in modern-day southern mainland Greece, the Aegean Sea, and Asia Minor.
The war was the consequence of a "cold war" between both powers, which had started in 196 BC. In this period, the Romans and the Seleucids attempted to settle spheres of influence by forging alliances with the small Greek city-states. Also important were the Romans and Seleucids' irreconcilable visions for the Aegean: the Romans saw Greece as their sphere of influence and Asia Minor as a buffer area while the Seleucids saw Asia Minor as a core part of their empire with Greece as the buffer zone.
After the Aetolian League triggered a small war which drew in Antiochus, Rome and the Seleucids came to blows. Antiochus landed in Greece but was forced to retreat across the Aegean after being defeated at the Battle of Thermopylae by the consul of 191 BC, Manius Acilius Glabrio. The Aetolians attempted to reach a settlement with the Romans but were unsuccessful in the face of excessive Roman demands. Antiochus' naval forces in the Aegean were defeated in two major engagements which saw the Roman coalition gain naval superiority. The consul of 190 BC, Lucius Cornelius Scipio, then pursued Antiochus into Asia Minor with the support of the Pergamene king Eumenes II.
Antiochus started peace negotiations, which he broke off after exorbitant Roman demands. But after he was defeated by the Roman-led coalition at the Battle of Magnesia, he sued for peace, accepting those Roman demands. In the resulting peace of Apamea, Antiochus ceded all of his territories beyond the Taurus Mountains to Roman allies and paid a large indemnity covering the Roman cost of the war. The Aetolians reached separate terms with the Romans, reducing them to a Roman client state, the next year. The Romans thereby gained uncontested hegemony over the Greek city-states in the Balkans and Asia Minor while also largely excluding the Seleucids from the Mediterranean.
Background and cold war
From 212 to 205 BC, Antiochus III campaigned to reassert Seleucid authority over Armenia and Iran. After reducing those areas to vassals and signing treaties with the Parthians and the Bactrians, he returned home. He then concentrated on restoring his empire's control over large portions of Asia Minor. He was, however, interrupted by the death of Ptolemy IV Philopator of Egypt in summer 204 BC, which gave him an opportunity to take Coele Syria, Phoenicia, and Judea from the Ptolemies in the aftermath of the Fifth Syrian War. Successful in Syria and Judea, he spent some time there before turning back to Asia Minor some time in 197 BC. For these victories, he took the title "Great King".With the conquests of Antiochus and the Roman victory in the Second Punic War, the Aegean was now flanked by two great powers on its east and west. Roman influence continued expanding as a result of the Second Macedonian War, fought between the republic and Philip V of Macedon. After Philip invaded the Cycladic islands and declared war on Rhodes and Pergamum, the defenders called on Roman aid in summer of 201 BC after major setbacks in the war. The Roman senate, influenced by a senatorial "circle of 'eastern experts'" led by Publius Sulpicius Galba Maximus, who were veterans of the First Macedonian War, sent an embassy to Philip with an ultimatum. Over the next three years, the Romans fought Philip and by 197 BC were victorious; in the aftermath, the Aegean's interstate politics had shifted considerably. The Roman coalition had defeated Philip, but Antiochus at the same time was consolidating Seleucid influence in western Asia Minor.
During the war, Antiochus' relations with Rome were cordial: at the start of the war, he had promised no aid to Philip before a Roman embassy; he complied with a Roman embassy demanding he withdraw from Pergamum, a Roman ally in the war; the Romans did nothing to prevent his occupation of areas further east in Asia Minor. After the war, however, Roman opinion soured, largely due to Antiochus' having crossed into Europe after the war's end, threatening Roman buffers in the Balkans, all while expressing a delayed congratulations to Rome. The Romans, in the peace after the Macedonian war, declared four towns – formerly Philip's possessions – to be free even though they were within Antiochus' sphere of influence.
The Romans also – in the aftermath of the war – proclaimed freedom for all Greeks, explicitly including even those in Asia Minor under Antiochus' control. The Romans gave a further warning against intervening in Greek affairs or entering Europe at the Isthmian Games of 196 BC. A later embassy reached the king at Lysimachia and demanded Antiochus' withdrawal from Ptolemaic lands in Asia Minor, his withdrawal from lands formerly Philip's, and that he refrain from attacking any Greek cities ; the Romans had no right to demand the last element and Antiochus deftly brushed off Roman demands by appealing to his historic claims in the region and protesting the lack of any legitimate Roman interest in Asia Minor after his marriage alliance with Ptolemy and his own declaration of freedom for the Greek cities in Asia Minor. His responses largely blunted any possible Roman causes for war: "if Rome had wanted to fight at this point, she would have had to fight for the freedom of cities that Antiochus free, for the settlement of disputes that he was willing to refer to arbitration, and for the return to Ptolemy of cities that Ptolemy apparently did not want back".
More fundamentally, however, the Romans and Antiochus had incompatible international visions: Rome saw their sphere of influence running directly to the Hellespont with Asia Minor as a buffer region; Antiochus saw Asia Minor as his sphere with Greece acting as a buffer. In the interim, Rome pursued a policy of building goodwill among the Greek states to avoid seeming the aggressor and, if attacked, to draw neutral cities to Rome's cause. Any Seleucid move against Greek cities would paint them as the aggressors.
Outbreak
Roman forces in Greece, under Titus Quinctius Flamininus, largely withdrew after proclaiming its freedom from Roman control or taxation in 195 BC. Antiochus, at the same time, operated a large army in Europe against tribes in Thrace through 194, moving into the Roman power vacuum and conceiving of the Roman withdrawal as a retreat. At a meeting between Antiochus' envoys in Rome, ten legates speaking on behalf of the senate made their position clear behind closed doors: if Antiochus wanted peace he would have to stay on his side of the Hellespont and Bosphorus; if he did not do so Rome would maintain its rights to intervene in Asia to protect its allies. Provocatively, Flaminius – one of the legates – then gave a public oration before the senate proclaiming Roman intentions to free the Greeks in Asia Minor while Antiochus' ambassadors, from fear of starting a war and without authorisation to accept the Roman terms or to reject them, could only plead negotiations continue. The senate by spring 192, clarified its position and would accept peace provided that Antiochus remained in Thrace.In late 193 BC, the Aetolian League – receptive to Antiochus' ambassadors as they returned from the embarrassment at Rome – sought to shake up the Roman settlement and draw both Rome and Antiochus into war for its own advantage. The Aetolians moved to form an alliance between themselves, Philip in Macedon, and Nabis in Sparta. The plans for an alliance failed, but Nabis was sufficiently persuaded to invade coastal cities in Laconia; the nearby Achaean League responded by moving in reinforcements and dispatching an embassy to Rome; Rome responded by sending four ambassadors to remind the Greeks of their continued interests. After Flaminius, one of the ambassadors, spoke to the Aetolian League, it responded by passing a decree to invite Antiochus to liberate Greece and arbitrate the dispute between Rome and Aetolia. This was a declaration of war and the Romans saw Antiochus' representatives in Aetolia as responsible. The Aetolians then moved troops to seize Sparta, Chalcis, and Demetrias. Successful only at Demetrias and able to convince Antiochus that the Greek cities were waiting enthusiastically to rebel against Rome, he landed at Demetrias and proclaimed he would liberate the Greeks from Roman subjugation.
This was the final provocation for the senate in Rome. The combination of the Aetolians and Antiochus was an unacceptable intrusion into Greece. The Romans responded by dispatching the praetor Aulus Atilius Serranus with a fleet to the Peloponnese and Marcus Baebius Tamphilus with two legions to Epirus. Further troops were levied and, in the new year of 191 BC, placed under the command of Manius Acilius Glabrio to conduct the war "against Antiochus and those in his empire".
The military conflict
Even before Glabrio and his consular army arrived, Antiochus' campaign was not going well. He was received extremely coolly by the Greeks. Roman declarations of liberty had real substance and his claim of Greek liberation compared unfavourably with it; his ostensible liberations of a few cities in Thessaly had required force against their indigenous governments. The Achaean League responded to his occupation of Demetrias by declaring war, justifying it with their Roman alliance.Thermopylae
The spring of 191 BC saw the Macedonians enter the war against the Aetolian League – they operated independently of the Romans – and occupy a number of towns in Thessaly. Antiochus moved on Acarnania, but was forced to withdraw when he heard of the incursion into Thessaly. By the time the consul Glabrio reached Thessaly, towns simply surrendered without a fight. Antiochus, receiving no reinforcements and heavily outnumbered by the Roman coalition, was forced to choose between retreat or doing battle where the coalition's numerical superiority would be minimised. He chose Thermopylae. The resulting battle was such an overwhelming defeat for Antiochus that he immediately fled Greece for Ephesus. Less than six months had elapsed from his arrival in Demetrias. With the Roman victory there, the Greek cities that sat on the sidelines quickly flocked to join the victors.Glabrio turned his eye towards the Aetolians and captured Heraclea that year before besieging Naupactus after peace negotiations – the Aetolian ambassadors sought to surrender, but the specific rites for surrender were unclear and vitiated by their need for ratification – fell apart. Succeeded by the consul of 190 BC, Lucius Cornelius Scipio and Lucius' able legate Scipio Africanus, Glabrio returned to Rome and celebrated a triumph. That year, the Roman fleet under Gaius Livius won a battle off Corycus forcing Antiochus' fleet to retreat to Ephesus; the Seleucids then assembled a newly built fleet in Cilicia under the command of Hannibal, who had years previously fled to Antiochus' court.
Prevented from crossing the Aegean directly, the Scipios stayed in Europe, where they oversaw a six-month truce with the Aetolians so that they could send envoys to the senate in Rome negotiate a peace. In the meantime, the Scipios marched on the land route for Asia Minor. Hannibal's fleet was stopped by the Rhodians at the Battle of the Eurymedon and the remaining fleet at Ephesus was destroyed by Livius' successor, Lucius Aemilius Regillus, in the Battle of Myonessus. The latter battle cemented Rome's control of the sea. Aemilius' victory forced Antiochus to withdraw in haste back across the Hellespont to Asia Minor. When the Romans advanced into Thrace, Antiochus' allies did nothing to stop them; when they crossed the Hellespont, he gave no contest.