August 15th is the Feast of the Assumption, the festival that celebrates the Virgin Mary's bodily assumption into heaven.
There is no scriptural foundation for this event; it rests solely on apocryphal literature from the 3rd and 4th centuries. Such writings relate that Mary was surrounded on her death-bed by the apostles when Jesus appeared and bore her soul away. Three days later angels carried Mary's body to Paradise, where it was reunited with her soul.
The Assumption was only declared an article of faith on November 1st 1950 when Pope Pius XII (r. 1939-58) issued the Apostolic Constitution, Munificentissimus Deus, in which it was affirmed that Mary, 'when the course of her earthly life was finished...was assumed (Latin assumpta est: taken up) body and soul into the glory of Heaven'.
This was the first time since the definition of Papal Infallibility in 1870 that the Pope had exercised the Infallible Magisterium, proclaimimg the doctrine of the Assumption in his own right.
The Assumption was first widely represented in 13th century Gothic sculpture, especially in portals of churches dedicated to the Virgin. In Renaissance art images of the Assumption usually consist of two elements, one above the other. In the upper part, the Virgin is borne aloft by angels (who often play musical instruments), while on the ground below the apostles are gathered around an empty tomb.
The city of Florence is blessed by two exceptionally beautiful bas-reliefs of the Assumption, respectively the work of Nanni di Banco (Duomo) and Andrea Orcagna (Orsanmichele).