Video from Drive Thru History
"The first Nativity scene probably occurred at a location now covered by the Church of the Nativity in Bethlehem. Remarkably, scholars consider this the oldest standing church in Israel. Originally built by Emperor Constantine's mother, Helena, in the 4th century, Emperor Justinian rebuilt the current structure in the mid-6th century. Later, the Persians spared the church when they were conquering the area in the early 7th century. Even though they were destroying everything with Christian connections, they came into the Church of the Nativity, looked up, and saw depictions of the Magi – the Wise Men in the Christmas story -- on the walls. The invaders realized these guys looked just like them, so they protected the church in honor of their likely ancestors." from video introduction.