Although only his books on the Roman Civil Wars survive in their entirety, large parts of Appian's book on the Syrian War, or Syriaca, have also come down to us. This book deals with the war that the Romans and the Seleucid king Antiochus III the Great fought in 192-188, but also discusses, as an appendix, the history of the Seleucid Empire. The Syriaca is a valuable source for the history of the ancient Near East between the reign of Alexander the Great and the Roman conquest.
The translation was made by Horace White; notes by Jona Lendering.
 At the end of this conversation Hannibal invited Scipionote[Publius Cornelius Scipio Africanus; 193 BCE.] to be his guest, and Scipio replied that he would be so gladly if Hannibal were not living with Antiochus, who was held in suspicion by the Romans. Thus did they, in a manner worthy of great commanders, cast aside their enmity at the end of their wars.
Not so Flamininus, for, at a later period when Hannibal had fled after the defeat of Antiochus and was wandering around Bithynia, Flamininus sent an embassy to king Prusias on other matters, and, although he had no grievance against Hannibal, and had no orders from the Senate, and Hannibal was no longer formidable to them, Carthage having fallen, he caused Prusias to put him to death by poison. There was a story that an oracle had once said: "Libyssan earth shall cover Hannibal's remains."
So he believed that he should die in Libya. But there is a river Libyssus in Bithynia, and the adjoining country takes the name of Libyssa from the river. These things I have placed side by side as memorials of the magnanimity of Hannibal and Scipio and of the smallness of Flamininus.
Outbreak of war
 Antiochus, on his return from Pisidia to Ephesus, entered upon the business with the Roman ambassadors and promised to leave the Rhodians, the Byzantines, the Cyzicaeans, and the other Greeks of Asia free and independent if the Romans would make a treaty with him, but he would not release the Aeolians and the Ionians, since they had long been accustomed to obey the barbarian kings of Asia. The Roman ambassadors came to no agreement with him - in fact, they had not come to make an agreement, but to find out his purposes. So they returned to Rome.
Thereupon an Aetolian embassy came to Antiochus, of which Thoas was the principal member, offering him the command of the Aetolian forces and urging him to embark for Greece at once, as everything was in readiness there. They would not allow him to wait for the army that was coming from upper Asia, but by exaggerating the strength of the Aetolians and promising the alliance of the Lacedaemonians and of Philip of Macedonia in addition, who was angry with the Romans, they urged his crossing.
He assembled his forces very hastily, nor did even the news of his son's death in Syria delay him at all. He sailed to Euboea with 10,000 men, who were all that he had in hand at the time. He took possession of the whole island, which surrendered to him through fear. Michithio, one of his generals, fell upon the Romans at Delium (a place sacred to Apollo), killed some of them, and took the rest prisoners.
 Amynander, king of the Athamanes, leagued himself with Antiochus for the following reason. A certain Macedonian, named Alexander, who had been educated at Megalopolis and admitted to citizenship there, pretended that he was a descendant of Alexander the Great, and to make people believe his fables he named his two sons Philip and Alexander and his daughter Apame. The latter he betrothed to Amynander. Her brother Philip conducted her to the nuptial ceremony, and when he saw that Amynander was weak and inexperienced he remained there and took charge of the government by virtue of this connection. By holding out to this Philip the hope that he would restore his ancestral kingdom of Macedonia to him, Antiochus secured the alliance of the Athamanes.
He secured that of the Thebans also by going to Thebes and making a speech to the people. He was emboldened to enter upon this great war relying most rashly on the Thebans, Amynander, and the Aetolians, and he made a reconnoissance of Thessaly to determine whether he should invade it at once or after the winter had passed. As Hannibal expressed no opinion on the subject, Antiochus, before coming to a decision, asked him his thought.
 Hannibal replied, "It is not difficult to reduce the Thessalians either now or at the end of winter, if you wish. Exhausted by much suffering they will change now to you, and again to the Romans, if any misfortune befalls you. We have come here without any army of our own, trusting to the Aetolians, who said that the Lacedaemonians and Philip would join us. Of these I hear that the Lacedaemonians are as hostile to us as the Achaeans are, and as for Philip I do not see him here helping you, although he can turn the scale of this war for whichever side he favors. I hold the same opinion as before, that you should call in an army from Asia as quickly as possible and not put any reliance on Amynander or the Aetolians. When your army comes, carry the war into Italy so that they may be distracted by evils at home, and thus harm you as little as possible, and make no advance movement for fear of what may befall themselves. The plan I spoke of before is no longer available, but you ought to employ half of your fleet in ravaging the shores of Italy and keep the other half lying in wait for opportunities, while you station yourself with all your land forces at some point in Greece near to Italy, making a feint of invasion and invading it at any time if you can. Try by every means to make an alliance with Philip, because he can be of the greatest service to whichever side he espouses. If he will not consent, send your son Seleucus against him by way of Thrace so that Philip likewise may be distracted by troubles at home, and prevented from furnishing aid to the enemy."
Such were the counsels of Hannibal, and they were the best of all that were offered; but, moved by jealousy of his reputation and judgment, the other counsellors, and the king himself no less, cast them all aside lest Hannibal should seem to excel them in generalship, and lest the glory of the exploits should be his - except that Polyxenidas was sent to Asia to bring an army.
 When the Romans heard of the irruption of Antiochus into Greece and the killing and capture of Romans at Delium,note[Novermber 192.] they declared war. In this way the war between them, which had been smouldering a long time, first actually broke out.
So great was the dominion of Antiochus, ruler of many powerful nations of upper Asia, and of all but a few on the sea-coast, who had now invaded Europe; so formidable was his reputation and so complete his preparation, so many and so famous had been his exploits against other peoples, from which he had earned the title of Great, that the Romans anticipated that this war would be long and severe for them. They had their suspicions also of Philip of Macedonia, whom they had lately conquered, and of the Carthaginians also, lest they should prove false to the treaty because Hannibal was cooperating with Antiochus. Other subject peoples were under suspicion lest revolution should break out among them in consequence of the fame of Antiochus.
For these reasons they sent forces into all the provinces to watch them without provoking hostilities. With them were sent commanders called six-axe men (praetors), so called because the consuls had twelve bundles of rods and axes (as the kings before them had), whereas the praetors had only half the dignity of the consuls and half the number of insignia of office.
As in cases of great peril they showed their anxiety for Italy also, lest there should be some weakening or revolt against them there. They sent a large force of infantry to Tarentum to guard against an attack in that quarter, and also a fleet to patrol the coast. So great was the alarm caused by Antiochus at first. When everything appertaining to the government at home was arranged, they raised an army to serve against Antiochus, 20,000 from the city and double that number from the allies, to cross the Adriatic in the early spring. Thus they employed the whole winternote[192/191 BCE.] in making preparations for war.