Madonna of the Girdle and Saints Margaret, Gregory, Thomas, Augustine, Raphael and Tobias

This altarpiece, commissioned in 1456 to Filippo Lippi, was the result of ten years of troubled development. The artwork, tempera on panel, features an almost square format of about 2 meters. It portrays one of the themes most dear to the religiosity of the city of Prato, the delivery of the "Sacred Girdle", by the Virgin Mary to Saint Thomas during her Assumption to Heaven.
In the centre of the painting, the Virgin Mary, seated on a throne of clouds and enclosed in an almond supported by two angels, hands her Girdle to Saint Thomas, who, incredulously, stretches his arms.
According to the painter, this belt is precisely the Sacred Girdle kept in Prato, as the same green colour and shape, with strings at both ends, are depicted in the painting.
The picture is enriched by the presence of saints particularly venerated in the Prato monastery, on a precious grassy carpet that could also allude to the city's name, as "Prato" means lawn in Italian.
On the left, Saint Gregory the Great attends the scene together with Saint Margaret, to whom the monastery was dedicated. She presents the client, Bartolomea Bovacchiesi, to the Virgin Mary. The client was at the time abbess of the monastery and is depicted in smaller dimensions than the saints, following medieval hierarchical proportions. However, on the right we find St Augustine, founder of the Augustinians to whose order the nuns belonged, and St Raphael the Archangel who holds the little Tobias by the hand.
The long and tedious execution of the painting is linked to the complex personal and love affairs between the painter Friar Filippo Lippi and Lucrezia Buti. The latter was a young nun forced by her Florentine family to take vows in the monastery where the artist - who also served as chaplain - had been appointed. The two fell in love. So, taking advantage of a moment of celebration such as the display of the Sacred Girdle, on 1 May 1456, Filippo Lippi fled from the convent with Lucrezia. A year later their first son, Filippino, was born, destined to become an even better-known painter than his father. 
This story was related by the sixteenth-century biographer Giorgio Vasari and it has also recently been verified by archival documents: In the process of painting the picture, Filippo would have fallen in love with Lucrezia, so much so that he reproduced the features of the young nun in the face of Saint Margaret.
The artwork, long interrupted following the artist's departure from the monastery, was probably completed around 1466. It featured extensive interventions by Fra' Diamante, Filippo's main collaborator. His involvement is evident in the meticulous attention to the depiction of fabrics, pearls and jewels, with sought-after three-dimensional effects, as well as the detailed rendering of grass.