All Hallows Eve

 Eve of the Feast of All Hallows, that is, All Saints Day. Because of the tradition of costuming and community gatherings, it has become popular in many locations that have little tradition of Christian holy days.

All Hallows' Eve falls on 31st October each year, and is the day before All Hallows' Day, also known as All Saints' Day in the Christian calendar. The Church traditionally held a vigil on All Hallows' Eve when worshippers would prepare themselves with prayers and fasting prior to the feast day itself.

The name derives from the Old English 'hallowed' meaning holy or sanctified and is now usually contracted to the more familiar word Hallowe'en.

A brief history of the festival
In the early 7th century Pope Boniface IV consecrated the Pantheon in Rome, formerly a temple to all the gods, as a church dedicated to Saint Mary and the Martyrs, and ordered that that date, 13th May, should be celebrated every year.

It became All Saints' Day, a day to honor all the saints, and later, at the behest of Pope Urban IV (d. 1264), a day specially to honor those saints who didn't have a festival day of their own.

In the 8th century, on 1st November, Pope Gregory III dedicated a chapel to all the saints in St. Peter's Basilica in Rome. Gregory IV then made the festival universal throughout the Church, and 1st November has subsequently become All Saints' Day for the western Church.