Judas
We won’t get too much into scripture here, but we all know that Judas is one of the all-time ultimate traitors. To get the biggest possible question out of the way, most historians agree that Jesus of Nazareth was indeed a real historical person. Judas as well is a true historical person.
Jesus was immensely influential in the Judea province during the reign of the Roman Emperor Tiberius. The Romans were apprehensive at best towards the Jewish population, but the growth of popularity and general intensity surrounding Jesus started getting more attention. The breaking point, however, was when Jesus began to be considered something of a king among the Jews.
The Romans had a complex when it came to kings, ironic because their emperors were basically kings, but the fears went all the way back to the earliest days of Rome. So, when Jesus achieved king status, not that Jesus thought of himself as a king, he was sought for a trial and possible execution.
Judas Iscariot was one of Jesus’ disciples and stuck with his teachings for years. When the Romans began searching for Jesus more intently, Judas decided to make a deal with the Roman governor to hand over Jesus for thirty pieces of silver. The last supper came and went with Judas present and fully planning on betraying Jesus. After the dinner, Judas identified Jesus to the waiting Romans who arrested him in the Garden of Gethsemane.
We all know what happened to Jesus afterwards. Judas reportedly returned his silver, feeling so ashamed of what he had done. The most likely account of Judas after the crucifixion of Jesus is that he hung himself. There are a lot of different interpretations of what happened and how, but most historians agree on most of the events listed here. One could argue that Judas was an essential piece of the puzzle that launched Christianity, but even so, he was no less of a traitor for his actions.