Judas Iscarlot:  another name of  'traitor', the disciple-turned-betrayer. Unlike the other eleven apostles who all were Gaileans, Judas was born in  the territory of Judah, an outisder. Most stories of Iscarlot tell how Jesus was sold to the High Priests by him, nearly no more details about this man. However, in the modern days, some scholars try to tell another story that without the help of Judas, Jesus could not fulfill his Saviour role. The most famous one is the newly discovered Gospel of Judas.  Sensationally, the manuscript portrays Judas  not as a villain but as a hero and Christ's favoured disciple. And it claims to repeat conversations between the two men and shows that in betraying Christ, Judas was fulfilling a divine mission. To learn the further details of the Gospel of Judas,  I highly recommend the National Geographic Site to you.    

I have also found another argument on the Internet that  Dr. Daryl Schmidt of Texas Christian University says Judas never existed, because he was a composite character, created to serve the anti-Semitic purpose of early Christians who blamed Jews for killing Jesus.