In 64 BCE the Roman general Pompey conquered Syria and intervened in the Hasmonean civil war in Jerusalem, restoring Hyrcanus II as High Priest and making Judea a Roman vassal kingdom. During the siege of Alexandria in 47 BCE, the lives of Julius Caesar and his protégé Cleopatra were saved by 3,000 Jewish troops sent by Hyrcanus II and commanded by Antipater, whose descendants Caesar made kings of Judea.