9:11 {8} And 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.
(8) The order of powers of maliciousness: that they are subject to one infernal king, whom you may call, The Destroyer: who drives the whole world both Jews and Gentiles into the destruction that belongs to himself. I cannot tell whether this name has respect to the etymological interpretation of Hildebrand, by a figure often used in the Holy Scripture: which albeit it may otherwise be turned of the Germans (as the sense of compound words is commonly ambiguous) yet in very deed it signifies as much as if you should call him, the firebrand, that is, he that sets on fire those that are faithful to him.
9:11 They had a king over them. The real king was not the star, but the power of the bottomless pit.
Apollyon. The destroyer; either the devil or one of his angels.
9:11 And they have over them a king - One by whom they are peculiarly directed and governed. His name is Abaddon - Both this and Apollyon signify a destroyer. By this he is distinguished from the dragon, whose proper name is Satan.
9:1-12 Upon sounding the fifth trumpet, a star fell from heaven to the earth. Having ceased to be a minister of Christ, he who is represented by this star becomes the minister of the devil; and lets loose the powers of hell against the churches of Christ. On the opening of the bottomless pit, there arose a great smoke. The devil carries on his designs by blinding the eyes of men, by putting out light and knowledge, and promoting ignorance and error. Out of this smoke there came a swarm of locusts, emblems of the devil's agents, who promote superstition, idolatry, error, and cruelty. The trees and the grass, the true believers, whether young or more advanced, should be untouched. But a secret poison and infection in the soul, should rob many others of purity, and afterwards of peace. The locusts had no power to hurt those who had the seal of God. God's all-powerful, distinguishing grace will keep his people from total and final apostacy. The power is limited to a short season; but it would be very sharp. In such events the faithful share the common calamity, but from the pestilence of error they might and would be safe. We collect from Scripture, that such errors were to try and prove the Christians, 1Co 11:19. And early writers plainly refer this to the first great host of corrupters who overspread the Christian church.