Solemnities, Feasts, and Memorials are days which are celebrated in commemoration of the sacred mysteries and events recorded in the history of our redemption, in memory of the Virgin Mother of Christ, or of His apostles, martyrs, and saints.
About the image: The Forerunners of Christ with Saints and Martyrs by Fra Angelico (circa 1395-1455). Part of a collection at the National Gallery in London, England.