Who Are the Angels Imprisoned in the Euphrates River? The Bible Reveals a Hidden Mystery? STEVE: The following video is excellent and also scriptural as far as I can see and includes the Book of Enoch. Who are the 4 angels bound in chains in the bottom of the Great river Euphrates? How do they compare with the 4 Horsemen? In Revelation 9 it talks about the 4 angels that are bound in the Great river Euphrates and that one day they will be released to slay 1/3 of the world’s population. Compare them with the 4 Horsemen of Death in the Book of Revelation chapter 6 These horsemen kill 1/4 of the world’s population.