It's nearly impossible to go through December without seeing at least one nativity scene, whether it's a set of ceramic figurines in a private home, a life-size tableau in front of a church, or a cast of actors in a children's pageant. And rarely does a year go by that these representations of Jesus, Joseph, Mary, the three wise men, some shepherds, and miscellaneous barn animals go unmolested by vandals or unchallenged by lawsuits. Why do people put up creches at Christmastime, anyway?
Blame St. Francis of Assisi, who is credited with staging the first nativity scene in 1223. The only historical account we have of Francis' nativity scene comes from "The Life of St. Francis of Assisi," by St. Bonaventure, a Franciscan monk who was born five years before Francis' death. According to Bonaventure's biography, St. Francis got permission from Pope Honorious III to set up a manger with hay and two live animals — an ox and a donkey — in a cave in the Italian village of Grecio. He then invited the villagers to come gaze upon the scene while he preached about "the babe of Bethlehem." (Francis was supposedly so overcome by emotion that he couldn't say "Jesus.") Bonaventure also claims that the hay used by Francis miraculously acquired the power to cure local cattle diseases and pestilences.
While this part of Bonaventure's story is dubious, it's clear that nativity scenes had enormous popular appeal. Francis' display came in the middle of a period when mystery or miracle plays were a popular form of entertainment and education for European laypeople. These plays, originally performed in churches and later performed in town squares, re-enacted Bible stories in vernacular languages. Since church services at the time were performed only in Latin, which few understood, miracle plays were the only way for laypeople to learn scripture. Francis' nativity scene used the same method of visual display to help locals understand and emotionally engage with Christianity.