Revelation 12:1-2 And a great sign appeared in heaven: a woman clothed with the sun, with the moon under her feet, and on her head, a crown of twelve stars. She was pregnant and was crying out in birth pains and the agony of giving birth

Israel was pregnant and gave birth to the Messiah.

Revelation 12:3,4 And another sign appeared in heaven: behold, a great red dragon, with seven heads and ten horns, and on his heads seven diadems. His tail swept down a third of the stars of heaven and cast them to the earth. And the dragon stood before the woman who was about to give birth so that when she bore her child he might devour it.

Satan has a powerful kingdom and rules over many angels he deceived. Satan failed when he tried to kill the baby, Messiah.

Revelation 12:5 She gave birth to a male child, one who is to rule all the nations with a rod of iron, but her child was caught up to God and to his throne

Jesus ascended into the heavens after he rose from the dead.

Revelation 12:7-9 Now war arose in heaven, Michael and his angels fighting against the dragon. And the dragon and his angels fought back,  but he was defeated, and there was no longer any place for them in heaven.  And the great dragon was thrown down, that ancient serpent, who is called the devil and Satan, the deceiver of the whole world–he was thrown down to the earth, and his angels were thrown down with him.

Many years will pass by and a war will break out in heaven and Jesus who is also called Michael will kick Satan and the fallen angels to earth for good.

Revelation 12:6 and the woman fled into the wilderness, where she has a place prepared by God, in which she is to be nourished for 1,260 days.

Bound to earth Satan will go after the woman (Israel) but many will escape into the wilderness and God will hide them for 42 months.

Revelation 12:17 Then the dragon became furious with the woman and went off to make war on the rest of her offspring, on those who keep the commandments of God and hold to the testimony of Jesus. And he stood on the sand of the sea

Many followers of Jesus will be beheaded by Satan during the great tribulation.

Revelation 12:11 And they have conquered him by the blood of the Lamb and by the word of their testimony, for they loved not their lives even unto death.

The Christians will overcome Satan by believing and standing on the Word of God and by their faith in Jesus.