Revelation 9:11

RV 'They have over them as king the angel of the abyss,' etc.

13-21. The sixth trumpet sounds, and a voice from the altar answers the prayers of the martyrs crying for vengeance, cp. Revelation 6:9. (Revelation 9:13), by commanding the four angels, bound at the Euphrates, to be loosed (Revelation 9:14). Immense armies of horsemen issue forth, and kill the third part, i.e. a large number, but not the whole, of the ungodly: cp. Revelation 9:20. The Euphrates is the river of Babylon, and Babylon in this book represents Rome. Perhaps, therefore, this vision speaks of devastation caused by Roman armies, possibly in the civil wars that followed the death of Nero.

In the 'four angels bound,' St. John uses a familiar Jewish apocalyptic idea. Each country was supposed to have its angel or angels (cp. Daniel 10:13; Daniel 10:20), 'Prince of Persia,' 'Prince of Greece,' and see on Revelation 1:20. The four angels would be the invisible representatives of the hosts of 'Babylon,' i.e. Rome, and their 'binding' or 'loosing' would represent the spiritual cause of the restraint or letting loose of the armies. The angels were held in leash until the exact moment foreordained by God (Revelation 9:15). As with the locusts, the details of the description probably have no special meaning.