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.
History of the Seleucid Empire (cont'd)
 Seleucus, the son of Theosnote and Laodice, surnamed Callinicus, "the triumphant", succeeded Theos as king of Syria.note
After Seleucus his two sons, Seleucus and Antiochus, succeeded in the order of their age.note As Seleucus was sickly and poor and unable to command the obedience of the army, he was poisoned by a court conspiracy in the second year of his reign.note
His brother was Antiochus the Great, who went to war with the Romans, of whom I have written above. He reigned thirty-seven years.note
I have already spoken of his two sons, Seleucus and Antiochus, both of whom ascended the throne. The former reigned twelve years,note but feebly and without success by reason of his father's misfortune.
Antiochusnote reigned not quite twelve years,note in the course of which he captured Artaxias the Armenian and made an expedition into Egypt against Ptolemy, who had been left an orphan with one brother.note While Antiochus was encamped near Alexandria, Popilius came to him as Roman ambassador, bringing an order in writing that he should not attack the Ptolemies. When he had read it he replied that he would think about it. Popilius drew a circle around him with a stick and said, "Think about it here." He was terrified and withdrew from the country, and robbed the temple of Venus Elymais; then died of a wasting disease, leaving a son nine years of age, the Antiochus Eupator already mentioned.note
 I have also spoken of Demetrius, his successor, who had been a hostage in Rome and who escaped and became king.note He was also called Soternote by the Syrians, the next who bore that title after the son of Seleucus I Nicator.
Against him a certain Alexander took up arms,note falsely pretending to be of the family of the Seleucids, to whom Ptolemy, king of Egypt, gave aid because he hated Demetrius. The latter was deprived of his kingdom by this means and died.note
His son, Demetrius,note drove out Alexander. For his victory over this bastard of the family he was surnamed Nicator by the Syrians, the next who bore that title after Seleucus. Following the example of Seleucus he made an expedition against the Parthians. He was taken prisoner by them and lived in the palace of king Phraates, who gave him his sister, Rhodogyne, in marriage.
 While the country was without a government Diodotus, a slave of the royal house, placed on the throne a young boy named Alexander, a son of Alexander Balas and of Ptolemy's daughter.note Afterward he put the boy to death and undertook the government himself and assumed the name of Trypho.
But Antiochus,note the brother of the captive Demetrius, learning in Rhodes of his captivity, came home and, with great difficulty, put Trypho to death. Then he marched with an army against Phraates and demanded his brother. Phraates was afraid of him and sent Demetrius back. Antiochus nevertheless fought with the Parthians, was beaten, and committed suicide.note
When Demetrius returned to his kingdom, he was killed by the craft of his wife, Cleopatra,note who was jealous on account of his marriage with Rhodogyne, for which reason also she had previously married his brother Antiochus.
She had borne two sons to Demetrius, named Seleucus and Antiochus Grypus (the Hook Nosed); and to Antiochus one son, named Antiochus Cyzicenus. She had sent Grypus to Athens and Cyzicenus to Cyzicus to be educated.
 As soon as Seleucusnote assumed the diadem after his father's death, his mother shot him dead with an arrow, either fearing lest he should avenge his father or moved by an insane hatred for everybody.
After Seleucus, Grypusnote became king, and he compelled his mother to drink poison that she had mixed for himself. So justice overtook her at last. Grypus was worthy of such a mother. He laid a plot against Cyzicenus,note his half-brother, but the latter found it out, made war on him, drove him out of the kingdom, and became king of Syria in his stead.
Then Seleucus,note, the son of Grypus, made war on his uncle and took the government away from him. The new sovereign was violent and tyrannical and was burned to death in the gymnasium at the city of Mopsus in Cilicia.note Antiochus,note the son of Cyzicenus, succeeded him. The Syrians thought that he escaped a plot of his cousin Seleucus on account of his piety, for which reason they gave him the name of Antiochus Pius. He was really saved by a handsome prostitute with whom he was in love. I think that the Syrians must have given him this title by way of joke, for this Pius married Selene, who had been the wife of his father, Cyzicenus, and of his uncle, Grypus. For this reason the divine vengeance pursued him and he was expelled the kingdom by Tigranes.note
 The son of Pius and Selene, who was brought up in Asia and was for that reason called Asiaticus,note was deprived of the government of Syria by Pompey, as I have already mentioned. He was the seventeenth king of Syria, reckoning from Seleucus (for I leave out Alexander and his son as being illegitimate, and also their slave, Diodotus), and he reigned only one year, while Pompey was busy elsewhere.
The dynasty of the Seleucids lasted 230 years. To compute the time from Alexander the Great to the beginning of the Roman domination there must be added fourteen years of the rule of Tigranes. So much, in the way of foreign history, concerning the Macedonian kings of Syria.