The Revelation to John, in the Twelfth Chapter:
And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
And prevailed not; neither was their place found any more in heaven.
And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
St. Michael Fighting Demons
Master of the Legend of St. Ursula
(active 1480-1500 in Bruges)
O EVERLASTING God, who hast ordained and constituted the services of Angels and men in a wonderful order; Mercifully grant that, as thy holy Angels always do thee service in heaven, so, by thy appointment, they may succour and defend us on earth; through Jesus Christ our Lord. Amen.