The Basilica dei Servi, particularly special to the Sienese, was for centuries the second Marian Sanctuary of the city until 1611, when the new Collegiate di S. Maria in Provenzano was built. From the outside, the building is devoid of any ornamentation, thus responding to the demands of the new Mendicant Orders for a simplicity of both message and form. The church, built according to an Egyptian plan, contains works of great value inside, both artistic and spiritual, dedicated for the most part to the Virgin Mary; the most significant are the Madonna del Bordone di Coppo by Marcovaldo, l’incoronazione della Vergine by Bernardino Fungai and la Madonna della Misericordia by Giovanni di Paolo. The Order of the Servi di Maria, also called simpy Serviti, was founded by the Seven Saints of Florence, who, after leaving their possessions and their familiy, withdrew to Monte Senario, far away from Florence, to dedicate themselves completely to prayer and pentience. Their example was contagious, so much that the way of life of the Servi di Maria started to spread, reaching Siena in 1250. 

Source: viaesiena.it