On this day of January 06, the church celebrates the manifestation in the eyes of the world of Jesus Son of God, the Messiah, the incarnate Word, before whom the Magi from the East ave come to bow down: It's the Epiphanie. In general, this date is a working day so the celebration of the second Sunday of the nativity in some countries.
This feast is also called "theophany" which means "manifestation of God". In the greek culture, we call "Epiphanes" the divinity such as Zeus, Athena, Hermes and Poseidon... who barge in the sight of men. But for us Christians it is Christ God who reveals Himself to the world according to the stories of Matthew 2, 1. 2. 10-12 that we celebrate. He manifests Himself in the form of a newborn baby at a moment in the history of the Jewish people; first with the simple people, the shepherds, then throughout the world in its diversity in the person of the Magi who are, according to the stories of different origins.
In the account of St. Matthew no name or number is attributed to these Magi, only the present three, hence the idea of the three Magi.
It is only in the 8th century that the first Latin text naming these Magi was discovered, a text presumably translated from a Greek text from Alexandria dating from the 6th century. Bede the Venerable, an English Benedictine, born in the 7th century, is credited with naming and describing the Magi. According to Bede, these three Magi represent the three known continents, including Asia, Africa and Europe. The first is Melchior, an old man with a beard and hairy, white skin, he presented gold as a sign of royalty. Then Gaspar, a young man with red skin, still hairless, who presented incense as a symbol of divinity. The third is Balthazar, a bearded man with black skin who presented myrrh as a reminder that the Son of Man must pass through death.
It was not until the 12th century that this visit of the Magi was celebrated in the Church. Relics from Milan have been identified as belonging to the Magi and those Frederick Barbarossa who moved them to Cologne. These relics are still kept in Cologne Cathedral.