In the war with Hannibal Scipio had maintained that future security demanded his decisive defeat, not merely his expulsion from Italy. The Senate now believed with Scipio that Antiochus must not merely be driven out of Greece, but must be defeated in his own country and forced well back from the Greek cities of Asia Minor. Only by reducing his kingdom from the rank of a great power could permanent peace be guaranteed. There is no justification for assuming that the motive for this decision was aggressive militarism. The man best suited to face the great king was obviously Scipio Africanus, but he could not be re-elected consul without violating the constitution, since he had held this office only three years before. The consuls elected for 190 were his brother Lucius Scipio and his friend C. Laelius; the former obtained the province of Greece with the right to cross to Asia. As Lucius was less experienced, his brother Publius was ‘associated’ with him without specific duties and so the conqueror of Hannibal held the effective command against Antiochus.9 The Scipios, who were to take over the two legions from Acilius, set sail with 8,000 reinforcements in March 190.
Meanwhile the Romans had determined to challenge Antiochus’ supremacy at sea by preparing 100 battleships. With 50 of these C. Livius Salinator, son of the victor of Metaurus, sailed across the Aegean to join Eumenes. The Rhodians, who till then had remained neutral, had to decide their policy. If Antiochus predominated in the Aegean, their trade would suffer; but the Romans, if victorious, would hardly maintain a permanent squadron there. Further, Rhodes was ill pleased that Eumenes should derive all the advantages from victory and so she decided to co-operate with Rome, forgetting that when once the old balance of powers was destroyed, she would be virtually dependent on the goodwill of the victor. Antiochus, who was holding the Dardanelles against the possibility of a Roman invasion of Asia, sent his fleet to defeat Livius and Eumenes before they joined the Rhodians (September). An action was fought off Cape Corycus, between Ephesus and Chios, in which Antiochus’ admiral, Polyxenidas, lost more than one-third of his ships. The Romans owed this important victory to their superior numbers and their grappling and boarding tactics: Antiochus was cut off from the Aetolians and deprived of the command of the sea, by which alone he might hope to contest the Roman crossing to Asia.
The Aetolian embassy which had come to Rome at the end of 191 had been offered hard terms: unconditional surrender or the immediate payment of 1000 talents and the renunciation of an independent foreign policy. Only by a decisive defeat could Rome expect to impose such conditions, which were naturally refused. Thus when the Scipios landed in Greece in April 190 they found that war had blazed out again and that Acilius had recommenced his siege warfare by capturing Lamia and besieging Amphissa. Wishing neither to spend time breaking up the Aetolian League piece by piece nor to leave behind them an unbeaten Aetolia or a Greece in which Philip could expand freely, they offered Aetolia a six months’ armistice. The Aetolians foolishly accepted, forgetting that further resistance would only be feasible if Antiochus remained unconquered; by this act they sacrificed any hope of help from him. The Scipios then despatched an energetic young man, Tiberius Sempronius Gracchus, the future son-in-law of Africanus and father of the Gracchi, to secure Philip’s co-operation. Learning that the king had supplies ready, they proceeded safely through Macedon and Thrace to the Hellespont. The fact that Philip remained loyal when he had the chance of destroying the Roman army on its march through these wild countries is perhaps a testimony to the magnetic personality of Africanus, who quickly won his friendship, as shown not least perhaps by the personal letter which he wrote to Philip describing his Spanish campaigns.
At the same time a naval campaign was conducted to win control of the Hellespont and to secure communications. Antiochus had spent the winter enlarging his navy; he increased Polyxenidas’ fleet to 90 warships, while Hannibal raised a second fleet in Phoenicia. A series of operations followed in which Livius and Eumenes were outmanoeuvred; Livius’ successor, Aemilius Regillus, at first fared little better. Success at sea encouraged Antiochus to negotiate (May–June); he needed a breathing space before renewing the war, such as the Romans had obtained in Greece by their truce with Aetolia. But Aemilius was persuaded by Eumenes to reject the king’s overtures. When news came that Hannibal was sailing up with another fleet, the Rhodians under Eudamus bravely sailed off to intercept him. Despite Hannibal’s superior force Eudamus outmanoeuvred him off Side in Pamphylia and thus shared with Scipio Africanus alone the glory of having defeated Hannibal in battle. Antiochus then saw his opportunity. Only part of the Rhodian fleet under Eudamus had rejoined the Romans, while Eumenes was at Troas; so Polyxenidas was ordered to attack the numerically inferior enemy. The fleets met off Myonnesus. Eudamus skilfully prevented an enveloping movement against the Roman vessels and held the Syrians’ wing while the Romans broke their centre. The battle gave the allies the command of the sea and opened the way for the Scipios to cross to Asia in safety.
Antiochus evacuated Thrace and did not try to contest the crossing to Asia. Avoiding all useless diversions he concentrated on mustering his army, summoning his allies of Galatia and Cappadocia. The Scipios, however, secured the neutrality of Bithynia.10 After receiving the surrender of Lysimacheia, where a large supply of provisions had unwisely been left undestroyed, they crossed the Hellespont, as their communications by land and sea were secure. For the first time a Roman army set foot in Asia. But the way was prepared by the number of allied or friendly states there: most of the Troad, Pergamum and Rhodes, and many cities on the Aeolian and Ionian coast. During a delay caused by the fact that as a Salian priest Africanus could not move for a month, Antiochus, clear-sighted and prudent, sent an envoy to offer terms. He would abandon Europe and break off relations with Aetolia; recognize the independence of Smyrna, Lampsacus and Alexandria Troas and of those Greek cities on the Aegean coast over which Rome wished to throw her aegis; finally he would pay half the cost of the war. These terms, which went considerably beyond what the Romans had claimed in 196, nevertheless left the power of Syria substantially intact. On his brother’s advice Lucius Scipio replied that Antiochus must withdraw from Asia Minor north and west of the Taurus Mountains and pay full costs. Antiochus refused, while his envoys failed to win Africanus’ co-operation by bribery and by offering to return his son who had been captured; incidentally thereby he provided Scipio’s political opponents in Rome with good propaganda.
Proceeding down the Asiatic coast the Romans were joined at Elea by Eumenes; but here P. Scipio fell ill and had to be left behind. His brother advanced inland towards Thyatira while Antiochus retreated eastwards, not to avoid battle, but to seek suitable ground where his cavalry, chariots, elephants and superior numbers would have full scope. He had gathered a host of some 75,000 men to face the 30,000 Romans; their fighting quality was good but the variety of their equipment and training made co-operation of the parts difficult. In a carefully chosen position in the plain of Magnesia-ad-Sipylum he fortified a camp between two rivers, the Phrygius and Hermus. The Romans camped on the opposite (western) side of the Phrygius and then crossing over offered battle with their flanks covered by the two rivers. Antiochus drew up his army but would not advance against the strong Roman position. A third time the Romans moved their camp nearer the enemy’s and again offered battle, though their right wing was unprotected; an engagement followed (probably in January 189).
The Roman weak spot was their exposed right wing in the south; here they massed their cavalry under Eumenes, hoping to defeat the enemy’s armoured horsemen before or while these attempted to outflank the Roman line. In this they succeeded. After the archers and slingers had scattered the Syrian scythe-chariots Eumenes charged home and thrust the cataphracts in confusion on to their own centre. Meantime Antiochus himself had led a successful charge of his Iranian horse on his right and had driven back the Roman left wing. But he repeated the error he had made at Raphia, by carrying on the pursuit instead of wheeling to support his centre or his broken left. The phalanx in the Seleucid centre had been drawn up with gaps between the columns and these had been filled with elephants. It stubbornly resisted the Roman legionaries until the elephants began to stampede and its flank was turned by Eumenes’ successful cavalry charge. Gradually giving way to the legions under Domitius Ahenobarbus, who was the real commander in Africanus’ absence, it was finally cut to pieces. The Syrian camp was captured and their losses were immense. Antiochus fled to Sardes and then to Apamea; when he saw his empire falling like a house of cards and the towns of Asia Minor surrendering to the Romans he laid down arms and sought terms. Thus the Romans had won Asia Minor, like Greece, at a single blow.11