The houses where acquired by the city council in 1405 from a wealthy merchant family named Römer which became the popular name for the complex of nine houses that form the Frankfurt city hall (Rathaus). The middle house (the actual Haus Römer) became the city hall and was later connected with the neighboring buildings. Located on the upper floor is the Kaisersaal ("Emperor's Hall") where the newly crowned emperors held their banquets. The Römer was partially destroyed in World War II and later rebuilt. The surrounding square, the Römerberg, is named after the city hall.