December 6 is the feast day of Saint Nicholas of Myra, patron saint of all children. Born to a well-off Christian family in the city of Patara, Lycia (an area in modern-day Turkey), between 261 and 280 AD, Nicholas supposedly lost both of his parents early in life and, having inherited a large fortune, donated it to the poor in great generosity. Nicholas then left for Myra, where he entered the priesthood, and was there elected as bishop by acclamation; there he also died on December 6, 343.
Many are the acts of charity and miracles traditionally accredited to the Saint: among them, one of the most famous is that of the three revived children. The legend goes that Nicholas, having stopped by an inn, saw three children being murdered by the innkeeper. Having seen their flesh preserved in salt, as so to use it as food to serve at that very inn, the Saint immediately started praying: the remains of the children then started to recompose and the three could safely get out of the barrels where their flesh was being preserved. Nicholas' prayer also sparked the innkeeper's final repentance and conversion to faith. For this miracle Saint Nicholas was given the patronage of all children; this, along with the great generosity of the Saint during his lifetime, generated the tradition of gift-giving on Saint Nicholas' day; his figure thus gradually evolved into the popular character of Santa Claus.
"Saint Nicholas and the three children", illumination from the manuscript "Breviary, use of Besançon", ms. 0069, f. 341r, before 1498, Bibliothèque municipale d'étude et de conservation, Besançon.