First Angelic War

"Then war broke out in heaven. Michael and his angels fought against the dragon, and the dragon and his angels fought back. But he was not strong enough, and they lost their place in heaven. The great dragon was hurled down—that ancient serpent called the devil, or Satan, who leads the whole world astray. He was hurled to the earth, and his angels with him."

- Revelations 12:7-10 The First Angelic War, also called the War in Heaven or Lucifer's Rebellion, was a conflict fought in the Kingdom of Paradise between angels led by the Archangel Michael who supported their father and rebellious angels led by Archangel Lucifer or Satan who wanted to overthrow him. The war ended in a victory for God and Michael and with the defeated rebels being exiled from Paradise,

Beginning
The roots of the First Angelic war began with the creation of Man. Yahweh asked all of his angels to bow before his new creation, which he considered to be his greatest. Lucifer refused, arguing that humans were flawed and abominations.

and couldn't possibly be made in God's image, and that Angels must be the ones made in the image of God.

This was the first time that God was disobeyed by one of his creations. Nevertheless, Yahweh didn't immediately expel Lucifer from Paradise.

War
Many angels felt betrayed by their father and jealous of humanity which made it easy for Lucifer to gather followers. He was able to recruit a third of the angels in heaven to join his rebellion and help him seize the throne of God.

Aftermath and Consequences
Following their defeat and exile, Satan and his rebels became known as the Angels of Darkness.