The great river Euphrates "The beginning of the end"

Revelation 16:4–12 (KJV 1900)
4 And the third angel poured out his vial upon the rivers and fountains of waters; and they became blood. 5 And I heard the angel of the waters say, Thou art righteous, O Lord, which art, and wast, and shalt be, because thou hast judged thus. 6 For they have shed the blood of saints and prophets, and thou hast given them blood to drink; for they are worthy. 7 And I heard another out of the altar say, Even so, Lord God Almighty, true and righteous are thy judgments.
8 And the fourth angel poured out his vial upon the sun; and power was given unto him to scorch men with fire. 9 And men were scorched with great heat, and blasphemed the name of God, which hath power over these plagues: and they repented not to give him glory.
10 And the fifth angel poured out his vial upon the seat of the beast; and his kingdom was full of darkness; and they gnawed their tongues for pain, 11 And blasphemed the God of heaven because of their pains and their sores, and repented not of their deeds.
12 And the sixth angel poured out his vial upon the great river Euphrates; and the water thereof was dried up, that the way of the kings of the east might be prepared.