The warrior-priests of the Knights Templar are probably one of the greatest mysteries of medieval times. Nearly everything about them, from their inception to end, is shrouded in a veil of uncertainty.
The first mystery is their origins. According to most histories, they were formed by a group of nine knights in 1118 after the end of the First Crusade resulted in the capture of Jerusalem. Their first leader was Hugues de Payen, a nobleman from Champagne, France. But why were they formed? One rumor is that they started as treasure hunters during the First Crusade. After Jerusalem fell, they excavated Solomon's temple, and the order was formed to protect it. That is only one version of their origins.
Another rumor is that the Templars were actually formed as the military arm of the Prieure De Sion, a very secretive groups of monks that at various times (all after the Templars) was said to include people such as Leonardo Da Vinci and Isaac Newton. According to this theory, the knights were formed in 1118 after the Prieure de Sion cut them loose.