They had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon.@Revelation 9:11
portrait
William Cowper (1731-1800)

William Cowper, Olney Hymns (London: W. Oliver, 1779), number 20.

Abbotsford Catholische Geistliche Gesänge (Andernach, Germany: 1608) (🔊 pdf nwc).

illustration
Angel with the Key to the Bottomless Pit
Albrecht Dürer (1471-1528)

My soul is sad and much dismayed;
See, Lord, what legions of my foes,
With fierce Apollyon at their head,
My heav’nly pilgrimage oppose!

See, from the over-burning lake
How like a smoky cloud they rise!
With horrid blasts my soul they shake,
With storms of blasphemies and lies.

Their fiery arrows reach the mark,
My throbbing heart with anguish tear;
Each lights upon a kindred spark,
And finds abundant fuel there.

I hate the thought that wrongs the Lord;
O, I would drive it from my breast,
With Thy own sharp two-edged sword,
Far as the east is from the west!

Come then, and chase the cruel host,
Heal the deep wounds I have received!
Nor let the pow’rs of darkness boast
That I am foiled, and Thou art grieved!