• The name of the chapel comes from a painting of Mary that was on a column in old St. Peter's nave. The painting was moved here in 1607. The chapel is also sometimes called Mater Ecclesiae or "Mother of the Church" which was the title the Second Vatican Council gave to Mary

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• During the reign of Pope Paschal II (1099-1118), the relics of St. Leo II (682-683), St. Leo III (795-816), and St. Leo IV (847-855) were placed in one urn. This urn is under the altar

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• In the floor, just outside the chapel, is the tomb of Pope Leo XII (1823-1829). On it he calls himself, "least among the heirs of so great a name." His monument is in the right aisle near the Pieta

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