(Δημήτριος), a Greek of the island of PHAROS in the Adriatic. He was in the service of the Illyrians at the time that war first broke out between them and Rome, and held Corcyra for the Illyrian queen Teuta; but treacherously surrendered it to the Roman fleet, and became a guide and active ally to the consuls in all their subsequent operations. (Plb. 2.11.) His services were rewarded, after the defeat and submission of Teuta, with a great part of her dominions, though the Romans seem never to have thoroughly trusted him. (Polyb. l.c.; Appian, App. Ill. ch. 8.) He afterwards entered into alliance with Antigonus Doson, king of Macedonia, and assisted him in the war against Cleomenes. (Plb. 2.65, 3.16.) Thinking that he had thus secured the powerful support of Macedonia, and that the Romans were too much occupied with the Gallic wars, and the danger impending from Hannibal, to punish his breach of faith, he ventured on many acts of piratical hostility. The Romans, however, immediately sent the consul L. Aemilius Paullus over to Illyria (B. C. 219), who quickly reduced all his strongholds, took Pharos itself, and obliged Demetrius to fly for refuge to Philip, king of Macedonia. (Plb. 3.16, 18, 19; Appian, App. Ill. 8; Zonar. 8.20.) At the court of this prince he spent the remainder of his life, and became his chief adviser. The Romans in vain sent an embassy to the Macedonian king to demand his surrender (Liv. 22.33); and it was at his instigation that Philip determined, after the battle of Thrasymene, to conclude an alliance with Hannibal and make war upon the Romans. (Plb. 5.101, 105, 108; Just. 29.2.) Demetrius was a man of a daring character, but presumptuous and deficient in judgment; and while supporting the cause of Philip in Greece, he was led to engage in a rash attempt to take the fortress of Ithome by a sudden assault, in which he himself perished. (Plb. 3.19.) Polybius ascribes most of the violent and unjust proceedings of Philip in Greece to the advice and influence of Demetrius, who appears to have been a man of much ability, but wholly regardless of faith and justice. (Plb. 7.11, 13, 14.)