From Matthew 2, NIV:
1bMagi from the east came to Jerusalem... 11On coming to the house, they saw the child with his mother Mary, and they bowed down and worshiped him. Then they opened their treasures and presented him with gifts of gold, frankincense and myrrh.
Nowhere does it say there were three Magi. For all I can tell from this passage, there could have been two, or thirty. The only clue I see about there being three is that three gifts are mentioned.
So what is the history behind the concept of three Magi in this story?