After the abdication of Grand Duke Wilhelm Ernst in 1918, the former residential palace of the Ernestine family became a cultural site in the Weimar Republic. The Provisional Government was briefly housed here during the National Assembly in Weimar. In 1923, however, the palace museum with the former Grand Ducal art collections was opened. The princely house, on the other hand, retained its right of residence in the modern south wing, which was only built just before the First World War. This book traces the more than a hundred years of use of the building between the old town and the Ilm on the edge of the Ducal Park. Cultural policy under four political systems repeatedly shaped the functions of the old center of power. As early as 1930, the National Socialists, who were part of the government in Thuringia early on, carried out a popular cleansing. While the exhibition in the halls of the castle museum followed the conceptual change in the art policy in force at the time, the national research and memorial sites for German classical literature founded in 1953 moved to the series of rooms that became available after the »Princely Expropriation« shortly after the foundation of the DDR. In some parts, the castle became a purely functional building. After reunification, the Stadtschloss was declared the "new center" of the Classic Foundation in 2008. After renovation, the former residence is to become the site of an open, democratic society that meets the needs of the public in the 21st century. Hardback edition, in the German language, 272 pages, 120 colour photos., size 27x27cm.