Charles Ellicott Commentary Revelation 12:3

"And there was seen another sign in heaven: and behold, a great red dragon, having seven heads and ten horns, and upon his heads seven diadems." — Revelation 12:3 (ASV)

And there appeared... — Better, And another sign was seen in heaven; and behold, a great red dragon. This, too, is a sign and has a meaning. The dragon stands for some dread and hostile power. “The dragon is that fabulous monster of whom ancient poets told, as large in size, coiled like a snake, blood-red in color...insatiable in voracity, and ever thirsty for human blood” — a fit emblem of him whom our Lord declared to be a murderer from the beginning; for the dragon is intended here to describe him who, in Revelation 12:9, is also said to be that old serpent, called the Devil and Satan.

The red color is the color of flame and blood, and the symbol of destruction and slaughter. The dragon is the emblem of the evil spirit, the devil, the perpetual antagonist of good, the persecutor of the Church in all ages : just as the dragon is sometimes employed to represent the Egyptian power, the ancient foe of Israel (Isaiah 51:9; Ezekiel 29:3).

Having seven heads and ten horns, and seven crowns (diadems) upon his heads. — This is the further description of the dragon. He is one, yet diverse; one, as an evil spirit; diverse, in the varieties of his power. The woman is but one: but her foe is multiform. She has one trust to keep, one work to do, and can only fulfill it in her Master’s way; evil is bound by no law, regards no scruple, and exerts its power through any channel and by every means.

Is there not also an assumption of divine likeness here in the use of the number seven? It is at least the representation of the great and worldwide power that he exercises as the prince of this world, whose kingdom is largely a parody of the true kingdom. The whole description should be compared with the account given of the beast in Revelation 17:3; Revelation 17:7; Revelation 17:10; Revelation 17:12.

There the seven heads are explained as seven kings, and the heads here are crowned; the ten horns are also explained as ten kings. The sevenfold kingship and the tenfold power of the world are thus described as belonging to the dragon.

The picture here, like the picture of the wild beast in Revelation 17:3, represents—as concentrated into a single hostile form—all the varying forces and successive empires that have opposed or oppressed the people of God and sought to destroy their efforts for good. This is because all evil has its root in a spirit at enmity with God. Consequently, the dragon appears armed with all the insignia of those sovereignties and powers that have been animated by this spirit.