In the Eastern church, the number of Magi is set at 12, but Western tradition sets the number at 3, probably based on the three gifts of gold, frankincense, and myrrh presented to the infant.

Frankincense is an aromatic gum resin containing a volatile oil that is used in incense and perfumes. It was highly valued in ancient times, both in worship and as a medicine. Myrrh is another aromatic offering—a bitter-tasting but agreeable-smelling gum resin, used as an ingredient of costly incenses, perfumes, and cosmetics; it also was used in medicines for local applications and in embalming.

Not originally, but the story of the Magi has been embellished over the years. As early as the 3rd century they were considered to be kings, probably interpreted as the fulfillment of the prophecy in Psalms 72:11 (“May all kings fall down before him”). In about the 8th century their names—Bithisarea, Melichior, and Gathaspa—appear in a chronicle known as the Excerpta latina barbari. They have become known as Balthasar, Melchior, and Gaspar (or Casper). According to Western church tradition, Balthasar is often represented as a king of Arabia or sometimes Ethiopia, Melchior as a king of Persia, and Gaspar as a king of India.