Parthian king Phriapatius reconquered the regions south of the Caspian Sea, and the Media Atropatene declared independence. Seleucus IV (r. 187-175 BC) was assassinated by a conspiracy of court officers; but his brother Antiochus IV Epiphanes (r. 175-163 BC), who had been a hostage in Rome, modernized the Seleucid army along Roman lines, and in 169 BC he sent troops east to Bactria and then attacked Memphis in Egypt. However, he had to withdraw before Roman power in Egypt, and his taking of the treasury from the temple at Jerusalem and his Hellenistic religious reforms brought on a Judean revolt. Shortly after the death of Antiochus IV, Judea and Commagene in Syria both became independent kingdoms during the reign of Demetrius I until he was killed and succeeded by Balas in Syria.