The Roman historian and orator Tacitus (c.55-120 AD) writes of the sequel to the Fire of Rome in 64 AD:
“Therefore to squelch the rumour that Nero had started the Great Fire of Rome, Nero created scapegoats and subjected to the most refined tortures those whom the common people called “Christians,” (a group) hated for their abominable crimes. Their name comes from Christ, who, during the reign of Tiberius, had been executed by the procurator Pontius Pilate. Suppressed for the moment, the deadly superstition broke out again, not only in Judea, the land which originated this evil, but also in the city of Rome, where all sorts of horrendous and shameful practices from every part of the world converge and are fervently cultivated.” (Annals 15.44)
Scholars acknowledge Tacitus as one of the best historians of his time. Being an obvious opponent of Christianity, the fact that he mentions Jesus’ crucifixion in this manner is considered as extremely strong corroboration by any normal historical standards. Another, arguably greater, significance is as confirmation of Nero’s persecution of Christians in Rome following the fire of 64 AD. As pointed out elsewhere, this event helps substantiate the early date of the New Testament documents themselves.
Some suggest Tacitus simply took his account from Christian sources: but the fact that he displays no knowledge of Christian doctrine, viewing them rather as an obnoxious cult, makes this improbable. Moreover, he is normally very careful in his Annals to distinguish between reported facts and those he regards as established beyond reasonable doubt, using phrases such as, ‘It is said,’ ‘Some have put it on record,’ etc. for hearsay, and even, ‘I have followed the majority of historians,’ or ‘the most numerous and trustworthy authorities,’ in areas where he acknowledges there to have been some dispute. Yet he writes of Jesus’ crucifixion as plain fact, with no qualification whatsoever.
If any doubt had existed as to the facts concerning Jesus’ death, Tacitus would scarcely have missed the chance to say so; and, as a Roman historian, he would have had ready access to the Imperial archives.