Epiphany — from the Greek epiphaneia, 'manifestation' — celebrates the revelation of Christ to the nations. In the West, the feast focuses on the visit of the Magi (Matthew 2:1-12), representing the Gentile world's recognition of Israel's Messiah. In the East, the feast centers on Christ's Baptism in the Jordan, where the Father's voice and the Spirit's descent revealed his divine Sonship. Originally a composite feast encompassing Nativity, Baptism, and the miracle at Cana, Epiphany is one of the oldest Christian celebrations, predating the December 25 Christmas.

The three gifts — gold (kingship), frankincense (divinity), and myrrh (suffering and death) — are scriptural, but the Magi's number (three) is tradition, inferred from the three gifts rather than stated in Matthew. Their traditional names (Caspar, Melchior, Balthasar) appear no earlier than the sixth century. Epiphany water blessing is an ancient Eastern custom associated with the Baptism/Theophany emphasis. The Western practice of chalking doors ('20 + C + M + B + 26') originated in medieval Europe; the letters represent either the Magi's names or the Latin blessing 'Christus mansionem benedicat.' The King Cake tradition, with a hidden figurine representing the Christ Child, developed in connection with the feast of the Three Kings.

Epiphany originated in the Eastern church. Clement of Alexandria (c. 200) attests followers of the teacher Basilides celebrating Christ's baptism on dates corresponding to January 6. The earliest explicit ecclesiastical reference comes from Ammianus Marcellinus in 361. In its original form, the feast was composite, commemorating three manifestations: Christ's birth, his Baptism in the Jordan, and his first miracle at the wedding at Cana.

A gradual 'exchange of feasts' occurred in the mid-to-late fourth century. As the West adopted December 25 for the Nativity, Rome adopted the Eastern January 6 celebration but shifted its focus to the Magi — Christ's manifestation to the Gentiles. The East, in turn, largely adopted December 25 for the Nativity while retaining January 6 for the Baptism (Theophany). The Armenian Church alone maintained the ancient composite celebration, observing both Nativity and Theophany on January 6 to this day.