Who was emperor when Jesus died?
Tiberius
During Tiberius' reign Jews had become more prominent in Rome and Jewish and Gentile followers of Jesus began proselytizing Roman citizens, increasing long-simmering resentments.[116] Tiberius in 19 AD ordered Jews who were of military age to join the Roman Army.[116] Tiberius banished the rest of the Jews from Rome and threatened to enslave them for life if they did not leave the city.[116]
Sources for the historicity of Jesus
Pliny the Younger (c. 61 – c. 112), the provincial governor of Pontus and Bithynia, wrote to Emperor Trajan "c". 112 concerning how to deal with Christians, who refused to worship the emperor, and instead worshiped "Christus". Charles Guignebert, who does not doubt that Jesus of the Gospels lived in Gallilee in the 1st century, nevertheless dismisses this letter as acceptable evidence for a historical Jesus.