Stephanie and Christoph Haas established the Ensemble Cosmedin in 1998, and it is today considered one of the leading ensembles for medieval and modern sacred music. The ensemble has appeared in the cathedrals of Chartres, Vézelay, Chur, Cologne, Mainz and Trier, in the Aachen Electoral Chapel, St Michael’s in Hildesheim, Ulm, Berne, Milan, Lugano, Strasbourg, Paris and Berlin. It has a number of recordings and television and radio features to its credit. The name of the ensemble is taken from a church in Rome, Santa Maria in Cosmedin, founded by Orthodox monks who took refuge in Rome after the iconoclastic dispute in Constantinople. They built near the Tiber a church ornamented with the most costly mosaics, soon known as Kosmidion (ornate). In Roman dialect this developed into Santa Maria in Cosmedin.