Based on the biography of Johann Casimir von Sachsen-Coburg (1564-1633), the author shows that this duke succeeded in building a new principality despite a difficult political starting position. This was created in 1572 by a resolution of the Reichstag after Casimir's father had lost the land because of felonia. Using predominantly unprinted source material, the book presents the symbolic and pragmatic investments in this princely development work. This included the creation of an efficient administration, the promotion of denominational education, the school system and the sciences, the enforcement of the "good" order as well as the formation of Coburg into a royal seat. In addition, this development work was marked by setbacks due to family tensions within the House of Wettin, to which Casimir belonged, and the negative consequences of the Thirty Years' War.