INNOCENTS' DAY or CHILDERMAS, a festival celebrated in the Latin church on the 28th of December, and in the Greek church on the 29th (O.S.) in memory of the massacre of the children by Herod. The Church early regarded these little ones as the first martyrs. It is uncertain when the day was first kept as a saint's day. At first it seems to have been absorbed into the celebration of the Epiphany, but by the 5th century it was kept as a separate festival. In Rome it was a day of fasting and mourn ing. The boy-bishop (q.v.), whose tenure of office lasted till Childermas, had his last exercise of authority then, the day being one of the series of days which were known as the Feast of Fools. Parents temporarily abdicated authority, and in nunneries and monasteries the youngest nun and monk were for the twenty-four hours allowed to masquerade as abbess and abbot. These mock eries of religion were condemned by the Council of Basel (1431) . The day is still observed as a feast day and merrymaking for children in Catholic countries. Innocent's Day was ever accounted unlucky, and Louis XI. used to prohibit any State business.