Revelation 9:14
saying to the sixth angel, who had the trumpet, Let loose the four angels, that are bound by the great river Euphrates.
Revelation 16:12
And the sixth angel poured out his vial upon the great river Euphrates; and its water was dried up, that the way of the kings from the east might be prepared.
Revelation 7:1
And after these things, I saw four angels standing at the four corners of the earth, holding the four winds of the earth, that the wind might not blow upon the earth, nor upon the sea, nor upon any tree.
Revelation 8:2
and I saw the seven angels, that stood before God; and seven trumpets were given to them.
Revelation 8:6
And the seven angels, that had the seven trumpets, prepared themselves to sound their trumpets.
Revelation 9:15
And the four angels were let loose; who were prepared for an hour, and a day, and a month, and a year, to kill the third part of men.