An alphabetical catalogue of the Roman churches described in the most important medieval guide for pilgrims to Rome, the Indulgentiae ecclesiarum urbis Romae , a source hitherto neglected by historical research. The list begins with the seven main churches in Rome followed by some 170 further places of worship. In each case the information found is grouped under different headings, including relics, indulgences, interiors and features, and provides an overview of the knowledge available in the late Middle Ages about Rome's churches and their characteristic features.