Why Do We Celebrate All Saints' Day?
Redeeming the Pantheon
Things improved dramatically for Christians after the Roman Emperor Constantine became a believer.
The first recorded church-wide All Saints’ Day was celebrated on May 13, 609, when Pope Boniface IV consecrated Rome’s Pantheon as a church. Built as a pagan temple to the Roman gods, the ancient architectural wonder was dedicated to Mary and all the martyrs. May 13 was declared the Feast of Mary and the Martyrs.
Why May 13? Some believe it was Boniface’s attempt to redeem the Roman Feast of the Lemures in which the malevolent and restless spirits of the dead were honored.