Flavius Josephus was the Roman name of Joseph ben Matthias.
Josephus during the second half of the first century AD, produced two long and detailed histories of the Jews and the events leading to the Roman victory in the Jewish Wars, History of the Jewish War and Antiquities of the Jews, but has almost nothing to say about Jesus and even that is probably added by Christians to fill a prominent gap left by the censors.
Josephus was born in Jerusalem only a few years after the crucifixion. He shows an interest in the Jewish religious groups of the time. He tells us about the Jewish religious parties, about John the Baptist who Christians say was the herald of the Messiah and about Jesus' brother, James, whose death he says was a reason for the start of the War in 66 AD. But he tells us nothing about the crucifixion or how it occurred. A man almost contemporaneous with Jesus and whose reputation was built on detailed histories of the Jewish people fails to mention him except in two brief passages, if they are genuine.
The precocious Josephus had studied all the Jewish religious sects before the age of 19 when he decided to become a Pharisee. He became a clerk to the Sanhedrin and at 26 went as an envoy to Rome to plead for some priests sent to Nero by Procurator Felix for trial. With the help of Poppaea, the Empress, who was possibly a Jewish proselyte or at least a godfearer, he succeeded.
He was thus in Rome at much the same time as Paul, the Apostle to the gentiles.