It tells how before the Great Flood, a group of 200 fallen angels called the Watchers ('Grigori' in Greek) looked upon the daughters of men, and lusted after them. They came down from heaven and chose themselves wives, and their children (the 'Nephilim') were giants and monsters who plagued the earth.
The Watchers also taught mankind all sorts of secrets: one of them, called Azazel, 'made known to them the metals of the earth', and showed them how to make swords and knives. Another, their leader Samjaza, taught them enchantments. Other Watchers taught them more secrets of civilisation, from cosmetics to astronomy. By these teachings the people of the world became unrighteous and turned away from God, and there was much conflict and suffering. In the end God ordered his angels to bind the Watchers, and sent the Great Flood to destroy their evil offspring.
What could this mean when seen through a Buffyverse lens?
A group of powerful shamans and magicians might have been seen as divine beings, even if they were only humans who knew the secrets of metalworking and magic. Of course, they might have learned or extorted those secrets from demons themselves... And they apparently showed a great interest in young women: perhaps not, as the writer of the Book of Enoch thought, for sexual reasons, but because they needed them as Slayers? (Of course, sex might have been part of it too: the Watcher-Slayer relationship need not always have been a chaste one.)
As for their children being monsters, perhaps the writer is confusing cause and effect: wherever there were Slayers and Watchers, there were likely to be demons and vampires too. A hostile witness might easily (or deliberately) assume that one brought the other, instead of vice-versa.
In the Book of Enoch, the Watchers were destroyed by angels and then the Great Flood. If we assume that the Flood was a historical event in ancient Mesopotamia, then we can posit the following hypotheses:
- That the Watchers openly held power in Sumeria in ancient times, by means of their magic, their command of metal-working, and their ultimate weapon, the Slayer.
- That their rule was unpopular enough that future generations would remember them as fallen angels, enemies of God.
- That their power was destroyed by an attack - perhaps by demons reacting to their success - and by a flood.
- And that afterwards, they resolved to stay in the shadows and become a secret society instead of an open power in the world.
Now to see if I can link in the Knights Templar and the Merovingian bloodline. :)