When the angel sounds the sixth trumpet a voice from the golden altar commands the angel to release the four angels who have been bound at the great River Euphrates. These four angels command a massive army which will kill one-third of mankind.
Who are these four bound angels appointed for this task? In Revelation 7:1 four angels were holding back the four winds. Aune thinks Revelation 7:1 and 9:13 refer to the same four angels (2:537), Charles does not (1:250). Since these angels are bound at the Euphrates River, they seem to be a different set of four than 7:1. Revelation does not identify these angels and it is unlikely they are four archangels, Michael, Gabriel, Suriel, and Uriel (1 Enoch 20:1).
There are a few references to destroying angels in Second Temple apocalyptic, although there are no examples of four angles appointed for the task. First Enoch 66:1 refers to “the angels of punishment who are prepared to come and release all the powers of the waters which are underground to become judgment and destruction unto all who live and dwell upon the earth.”
The Euphrates River is to the north and east of Jerusalem and many of Israel’s enemies in the Old Testament came from the east. Both Assyria and Babylon came from beyond the Euphrates River. After the exile Judea was controlled by the Ptolemies in Egypt to the south and the Seleucids in Syria to the north.
From the perspective of the late first century, the Euphrates could refer to eastern edge of the Roman empire. The Parthian empire controlled the east and Rome was concerned to control their eastern frontier against them. Since the Parthians were fierce warriors who used horseman in battle, many commentators interpret this large cavalry as a reference to the Parthians. Sibylline Oracles 14.66 refer to the “arrow-shooting Parthians of the deep-flowing Euphrates.”
The Sibylline Oracles refer to the Parthians several times. “Then the strife of war being aroused will come to the west, and the fugitive from Rome will also come, brandishing a great spear, having crossed the Euphrates with many myriads” (Sib. Or. 4.137–139). In 13.122–124 the “fugitive of Rome” crosses the Euphrates “with many myriads, who will burn you down and dispose everything badly.”
The size of the army is enormous, “twice ten thousand times ten thousand” (δισμυριάδες μυριάδων). Since the word myriad (μυριάς) refers to a very large, imprecise number (BDAG), Aune suggest the phrase be translated as “uncountable” (Aune 2:539). Psalm 68:17 describes an angelic army in similar terms, “The chariots of God are tens of thousands and thousands of thousands.” In 4 Ezra 13:5, Ezra sees “an innumerable multitude of men were gathered together from the four winds of heaven to make war against the man who came up out of the sea.” The man from the sea is a messianic figure based on Daniel 7.
Although popular prophecy teachers often associate this large number with China, a massive empire to the east of modern Israel, that is not at all the point of this massive uncountable army. A better explanation is to see this army as a demonic horde. The description of these demonic soldiers is intentionally horrifying:
Their breastplates were fiery red, dark blue, and yellow as sulfur. The breastplate probably refers only to the riders, there are many examples of breastplates for horses.
The heads of the horses resembled the heads of lions. A horse is not a terrifying animal, but a horse-sized animal with a head of a lion certainly is! Aune compares this lion-headed horse with “the widely distributed depictions of the Chimaera” (Aune 2:540).
Out of their mouths came fire, smoke and sulfur. Fire-breathing creatures are associated with judgement in early Jewish texts. For example, in Job 41:19 Leviathan breathed fire. Beale suggests these creatures allude Job’s description of Leviathan, associating these beasts “with Satan and his deceptive work” (515). Fourth Ezra 13 the messianic figure breaths fire on the uncountable multitude utterly destroying them.
4 Ezra 13.8-11 After this I looked, and behold, all who had gathered together against him, to wage war with him, were much afraid, yet dared to fight. 9 And behold, when he saw the onrush of the approaching multitude, he neither lifted his hand nor held a spear or any weapon of war; 10 but I saw only how he sent forth from his mouth as it were a stream of fire, and from his lips a flaming breath, and from his tongue he shot forth a storm of sparks. 11 All these were mingled together, the stream of fire and the flaming breath and the great storm, and fell on the onrushing multitude which was prepared to fight, and burned them all up, so that suddenly nothing was seen of the innumerable multitude but only the dust of ashes and the smell of smoke.
Their tails were like snakes, having heads with which they inflict injury. Like the locust in Revelation 9:1-11, the tails of these beasts are deadly.
As Greg Beale suggests, “the sixth trumpet intensifies and develops further the woe of the fifth” (Revelation, 513). The demonic oppression in the fifth trumpet had the power to torment, but not kill. This sixth trumpet kills one-third of the earth. Neither this destructive army nor the locust in the fifth trumpet refer to modern warfare or modern nations. They depict terrifying demonic oppression.