]The Massacre of the Innocents is an episode of infanticide by the King of Judea, Herod the Great: he ordered the execution of all young male children in the village of Bethlehem, to avoid the loss of his throne because of the newborn King of the Jews whose birth had been announced to him by the Magi.
“Then was fulfilled that which was spoken through Jeremiah the prophet, saying, A voice was heard in Ramah, Weeping and great mourning, Rachel weeping for her children.”…
The infants, known in the Church as the Holy Innocents, have been claimed as the first Christian martyrs. Traditional accounts number them at more than ten thousand, but more conservative historicizing estimates put their number in the low dozens, but there is dispute over whether the story is historical.
The commemoration of the massacre of these “Holy Innocents”—considered by some Christians as the first martyrs for Christ — first appears as a feast of the western church in the Leonine Sacramentary, dating from about 485. The earliest commemorations were connected with the Feast of the Epiphany, 6 January: Prudentius mentions the Innocents in his hymn on the Epiphany. Leo in his homilies on the Epiphany speaks of the Innocents. Fulgentius of Ruspe (6th century) gives a homily De Epiphania, deque Innocentum nece et muneribus magorum.
Today, the date of Holy Innocents’ Day, also called Childermas or Children’s Mass, varies. 27 December is the date for West Syrians (Syriac Orthodox Church, Syro-Malankara Catholic Church, and Maronite Church) and East Syrians (Chaldeans and Syro-Malabar Catholic Church). 28 December is the date in the Church of England, the Lutheran Church and the Roman Catholic Church (in which violet vestments were worn before 1961, instead of red, the normal liturgical colour for celebrating martyrs). The Eastern Orthodox Church celebrates the feast on 29 December.
In Spain and Hispanic America, December 28 is a day for pranks, equivalent to April Fool’s Day in many countries. Pranks are known as inocentadas and their victims are called inocentes, or alternatively, the pranksters are the “inocentes” and the victims should not be angry at them, since they could not have committed any sin. In some cultures it is said to be an unlucky day, when no new project should be started.
In addition, there was a medieval custom of refraining where possible from work on the day of the week on which the feast of “Innocents Day” had fallen for the whole of the following year until the next Innocents Day. This was presumably mainly observed by the better-off. Philippe de Commynes, the minister of King Louis XI of France tells in his memoirs how the king observed this custom, and describes the trepidation he felt when he had to inform the king of an emergency on the day.