Two wonderful and deeply moving pictures tell their story:
The first Christmas presents ever (Adoration of the Magi, Murillo)
Caspar, kneeling, has just presented his golden casket; the bare-headed Melchior and beturbanned Balthazar await their turn, with frankincense and myrrh respectively.
It's nice to see the figure of Joseph, the enigmatic and possibly bewildered stepfather smiling kindly over Mary's shoulder at the proceedings. I've always thought that he was quite entitled to maintain "She's not the Mother of God, she's a very naughty girl", pace The Life of Brian.
Note the Star of Bethlehem overhead.