Compline [Latin completorium completion], also known as the night office, is the final office of the day. It is contemplative in nature, with a focus on cultivating spiritual peace.
In The little office of the blessed Virgin Mary, Compline is associated with the coronation of the Virgin. This tradition derives from a descriptive passage found in Revelation. The Catholic Church extrapolated an image from that text, creating the event of Mary's coronation. The coronation is the completion or culminating event in the Mary narrative, much like Compline is the completing practice of the daily office.
1 And there appeared a great wonder in heaven; a woman clothed with the sun, and the moon under her feet, and upon her head a crown of twelve stars:
2 And she being with child cried, travailing in birth, and pained to be delivered.
3 And there appeared another wonder in heaven; and behold a great red dragon, having seven heads and ten horns, and seven crowns upon his heads.
4 And his tail drew the third part of the stars of heaven, and did cast them to the earth: and the dragon stood before the woman which was ready to be delivered, for to devour her child as soon as it was born.
5 And she brought forth a man child, who was to rule all nations with a rod of iron: and her child was caught up unto God, and to his throne.
6 And the woman fled into the wilderness, where she hath a place prepared of God, that they should feed her there a thousand two hundred and threescore days.
7 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
8 And prevailed not; neither was their place found any more in heaven.
Revelation 12:1- 8 [KJV]