Josephus was a Jewish priest who was given command of the Jewish forces in Galilee during the First Roman-Jewish War. After their defeat, he formed a suicide pact with the remaining members of his forces but failed to carry out his own suicide. After being taken captive by the Romans, he told the commanding general, Vespasian, that the star that had appeared suddenly in the skies was a portent that Vespasian would soon become emperor of Rome, saying that the star was also evidence that Vespasian was the Messiah that the Jews had been waiting for. When the prophecy came true, Vespasian adopted Josephus into his own household and allowed him to use the family name, Flavius.
Josephus wrote a number of histories of the Jews, but they were largely ignored by the Jews and soon forgotten by the Romans. The works of Josephus survived because they were adopted by the early Christians, who believed they saw in them evidence of the historicity of the Christian story.