The abbey, founded in 780, hosted from the beginning a community of cloistered Benedictine nuns. In the 12th century, the church was enlarged and consecrated under the name of Santissima Assunta (Our Lady of the Assumption). In 1810 the convent was officially suppressed, but a group of nuns remained in the guesthouse, returning to the convent after the defeat of Napoleon.
After the subsequent suppression of the religious orders in 1866, the community was allowed to remain in the convent, but it was put up for auction by the government. The nuns, however, managed to buy the monastery through an intermediary.
Inside the abbey we find a great cross above the main altar, dating from the 12th century and attributed to the so-called Master of Rosano.
Recently the precious painting has undergone restoration conducted to evaluate its state of preservation and to study the techniques adopted by the artist.
Surprisingly, a recess concealed in the vertical arm of the cross was discovered. It contained a relic, a piece of bone and a little cross made of stone, like those brought back from the Holy Land by the Crusaders. Some scholars think this work may have been commissioned after 1130, when Sofia took the veil. She belonged to the illustrious Guidi family, members of the Tuscan nobility and great landowners, and was the orphaned child of Guido Guerra, who probably died of disease contracted in the Holy Land.