The Oratory of the Compagnia di San Bernardino in Siena is a place of worship where the Diocesan Museum of Sacred Art has been housed in some adjoining rooms. The museum offers an overview of Sienese painting between the 13th and 17th centuries. In the vestibule that communicates with the upper oratory there are a number of panels by Sano di Pietro and other artists and a relief by Giovanni d'Agostino depicting the 'Madonna and Child with Two Angels', his only signed work. The oldest work is the 'Madonna di Tressa', an eponymous work by the Maestro di Tressa. The tondo with the 'Madonna and Child' by the Maestro degli Aringhieri dates from the end of the century. Some 14th-century frescoes from the church of San Francesco are the work of Pietro Lorenzetti and Ambrogio Lorenzetti, the latter also the author of the 'Madonna del Latte'.