They are a Christmas card staple – the three kings who followed a star to the baby Jesus. But one of them caused a revolution in art. We unravel the mystery of the Magi

They came bearing gifts of gold, frankincense and myrrh. This description of the Magi, the three kings or wise men who followed a star to the newborn Jesus, has always given artists plenty of scope to depict ornate boxes, cups and vessels. Paintings show them followed by pages, servants, soldiers and pack animals – an entire royal retinue. Dressed in their finest, making their way across deserts and over mountains guided by a light, these pilgrims to the lowly stable always look magnificent.

Although the Gospel of Matthew does not give individual names to this regal trio, we know them as Balthasar, Caspar and Melchior, thanks to a Greek manuscript from AD500. It was in the middle ages, too, that they were promoted from astronomers to kings. And a text attributed to the Venerable Bede, the historian monk from Northumbria, makes Balthasar black. Despite Bede’s assertion, there are very few images of a black Balthasar before 1400, possibly because medieval Europeans had so little concept of Africans. It was only with the dawning of the Renaissance that Balthasar’s colour began to be emphatically depicted. In fact, the trumpeting, joyous festive subject of “the adoration” inspired some of the richest portrayals of black people in European art.