Probably the most prominent visitor to the house at Herderplatz 16 was Duke Carl August, who regularly visited his long-time mistress Caroline Jagemann there. The beautiful and talented opera singer was appointed to the Weimar court theater by Goethe in 1797. With the connivance of his wife, Duchess Luise, Carl August bought his mistress the prestigious house next to the town church of St. Peter and Paul. The building looks back on a long history. It was first mentioned in a document around 1200 as the "Deutschritterhaus". It was given its current Renaissance façade in the mid-16th century.