How St. Francis changed the way we celebrate Christmas
Less than a month after the papal approval of the Regula Bullata [the Rule for the Order of Friars Minor], Francis arrived at the brothers’ hermitage in the little town of Greccio – a community in the vicinity of Rieti, located about halfway between Assisi and Rome. It was now December, and Francis had long been nurturing a heartfelt desire to celebrate Christmas in a wonderful new manner. He wanted others to share his own inner joy and exaltation at what for him was the most important feast of the year, since our salvation was heralded by the birth of Christ. He conceived of a simple way to awaken everyone’s love and admiration of the Christ Child, especially those who were weak in the Faith. 
His plan was to have Christmas Midnight Mass celebrated in the presence of a realistic representation of the humble grotto of Bethlehem, complete with live animals. “For I wish to do something that will recall to memory the little Child who was born in Bethlehem and set before our bodily eyes in some way the inconveniences of his infant needs . . .”  According to St. Bonaventure, he even obtained the approval of Pope Honorius, so that he would not be accused of willfully introducing novelty into the sacred ceremonies. 
Francis had arranged beforehand to have his friend, the nobleman Giovanni Velita, make the necessary preparations and help spread word of the event.  A little manger or crib was set up in the woods near the hermitage, filled with the common, coarse hay that beasts of burden feed upon. An ox and an ass were then led to the place. Some later embellishments of the story maintain that figures of Mary and Joseph were also positioned about the manger.  Francis was delighted to see everything ordered as he had wished. To the Poverello, “The sight of the crèche [manger scene] in its glorious simplicity was a symbol of the advent of lowliness, the exaltation of poverty, the praise of humility.” 
A host of brothers from near and afar descended upon Greccio, arriving from numerous friaries and villages. They joined with the crowds of local residents, field workers, and shepherds; all were drawn towards the manger where Francis knelt. The candles and torches of the onlookers brightened up the crisp night, reflecting their glow upon a light snow that had begun to fall. The sound of hymns echoed in the hollows and woodlands. Men and beasts and even nature itself radiated great joy on that special Christmas Eve – it was truly the feast of hearts. “The woods rang with the voices of the crowd and the rocks made answer to their jubilation.” 
The Holy Sacrifice of the Mass was celebrated at midnight with great solemnity, using an altar that had been erected over the manger. Francis, vested in his Deacon’s robes, sang the Gospel in a voice characterized by Celano as sweet, clear, strong and sonorous. 
He preached a touching sermon, describing the first Christmas and the humble surroundings of Mary and Joseph at the nativity of Son of God, whom he lovingly referred to as the Child of Bethlehem. During the ceremony, Giovanni Vileta experienced a vision in which he saw a babe lying in the crib, rapt in a slumber so deep that he appeared lifeless. Then he saw St. Francis approach and take the child in his arms, rousing him from his sleep.  For his biographer Celano, this vision aptly symbolized the mission of the saint: “ . . . for the Child Jesus had been forgotten in the hearts of many; but, by the working of his grace, he was brought to life again though his servant St. Francis and stamped upon their fervent memory.” 
The after-glow from that evening of devotion was manifested throughout the area in the days that followed. Many miraculous healings occurred among the sick, who were prayed over and touched with some of the hay that had lain in the sacred manger. Even infirm animals that were given the stalks of that hallowed grass for their food were restored to health. The influence and “after-glow” of that night in 1223 persists to this day, since it is generally accepted that the popularity of Christmas Eve crèches - mangers, nativity cribs - was inaugurated by St. Francis in Greccio.
11. St. Bonaventure, Major Life, Chapter 10, no. 7; pp. 710-711 Omnibus.
12. Celano, First Life, Book One, Chapter 30, no. 84; p. 300 Omnibus.
13. St. Bonaventure, Major Life, Chapter 10, no. 7; pp. 710-711 Omnibus.
14. Chalippe, p. 251.
15. Crib. By Stephen M. Donovan, in The Catholic Encyclopedia, Vol. IV, 1908, p. 488, http://www.newadvent.org/cathen/04488c.htm.
16. Fortini, p. 684 (present author’s translation).
17. Celano, First Life, Book One, Chapter 30, no. 85; p. 300 Omnibus.
18. Ibid., no. 86, p. 301.
19. St. Bonaventure, Major Life, Chapter 10, no. 7; p. 711 Omnibus.
20. Celano, First Life, Book One, Chapter 30, no. 86; p. 301 Omnibus.
Taken from chapter 15 of St. Francis of Assisi and the Conversion of the Muslims,
by Frank M. Rega, TAN Books and Publishers, Inc., 2007.