The Epiphany is a Christian feast day that is celebrated in January every year in Vatican City. This holiday, also known as Theophany in Eastern Christianity, Three Kings' Day in some Western cultures, commemorates the manifestation of Jesus Christ to the Gentiles, as represented by the Magi (Three Wise Men). The name 'Epiphany' comes from the Greek word 'Epiphania' meaning 'manifestation' or 'appearance'.

Vatican City, as the center of the Roman Catholic Church, observes this holiday with great devotion and fanfare. The Pope himself leads the main event, which is a grand mass service held at St. Peter's Basilica, featuring sermons, singing of hymns, and Holy Communion. This contributes to the remarkable spiritual ambiance of Vatican City during this period and attracts a plethora of worshippers and tourists from around the world.

Epiphany in Vatican City doesn't only revolve around religious activities. There are also traditional customs associated with this holiday such as the blessing of homes. Some believe that marking the door with the initials of the three kings, CMB (Caspar, Melchior, and Balthazar), together with the current year, brings luck and blessings. This represents another cultural aspect of Epiphany, reflecting the deep-rooted faith and belief systems of people and making Epiphany more unique and special in Vatican City.