Optional Memorial of the Dedication of St. Mary Major Basilica in Rome; first raised by Pope Liberius in the mid-4th Century, completed in 1743; it has survived many restorations without losing its character as an early Roman basilica; the feast day is also known as "Our Lady of the Snows"--a wealthy couple pledged their fortune to the Mother of God, and as an affirmation, she produced a miraculous summer snowfall and told them to build a church on the site