With Harold Camping's recent prediction about Doomsday being May 21, 2011, many people are being drawn to Doomsday theories. Doomsday theories date all the way back to the death of Jesus.

In the year 156 AD, a man named Montanus declared himself to be the personification of the Holy Spirit, but was later declared a heretic. Since then there have been hundreds of Doomsday predictions that have intrigued and baffled numerous people.

Though majority of Doomsday theories have religious backgrounds, the Bible clearly warns of the groundlessness of the specific predictions, as they are contrary to Matthew 24:36 No one knows about that day or hour, not even the angels in heaven, nor the Son, but only the Father.

Most prophets of doom tend to quickly gather their devotees whose belief is so fervent that they are willing to sacrifice their finance, family, and even their own lives. Who cares about anything when you can be sure that the end of the world is merely days away?

Click on the slideshow to check out these 10 Doomsday aka End Time aka Judgment Day scenarios since the 20th century that haven't quite worked out, but has established those making the Doomsday predictions as false prophets.