Flavius Josephus was a Jewish historian and soldier who was born in Jerusalem and lived from 37 A.D. to 100 A.D. He was born into a distinguished priestly family, and with the benefit of a good education and association with distinguished scholars he began to develop his intellectual gifts.
He commanded the Jewish forces in Galilee in their revolt against Rome in AD 66, even though he advocated against the war as he thought they would face certain defeat. However he was captured by emperor Vespesian but his life was spared when he presented himself as a prophet and foretold that the war had been prophesied and that a world ruler would now arise from Judea. He suggested to Vespesian that he was that ruler and was destined to become Emperor of Rome. This gained him the favour of the Roman emperor Vespesian and his life was spared. In AD 69 this prophecy came true, and Vespesian became Emperor he rewarded Josephus and adopted him into his own family.
The writings of Josephus provide an important background for our understanding of both the beginning of modern Judaism and of the New Testament. He wrote The Jewish War- a history of the Jewish revolt against the Roman empire from 66-74AD, and Antiquities of the Jews - the history of the Jews prior to the revolt. But how credible and accurate was Josephus, and what were his sources of information?
Much of the source of Josephus's information came from the Roman commentaries at least for his book war. And the source of these commentaries was either the memoirs written by Emperor Vespesian, or they were field reports of military commanders during the war of independence (66-74 AD), or perhaps based on his own accounts during this war as he spent much of his time assisting Vespesian's son Titus in understanding and negotiating with the Jews. No doubt some of his work was bias in favour of the Romans in order to try and impress them and remain in favour with them.
Among them were his ability to record events, which for many years later were relied upon for being a source of accurate information of the life and times of Jesus Christ.