Even after the German campaign that put an end to the War of the Sixth Coalition in the Napoleonic Wars, Sien remained a mayoralty in the Saxe-Coburg-ruled Principality of Lichtenberg with its capital at Sankt Wendel. This territorial arrangement was set forth at the Congress of Vienna. It retained the status when the Prussians took over in 1834. In Saxe-Coburg times, and Prussian times, too, the "Bürgermeisterei" (“Mayoralty”) of Sien comprised Sien and Sienerhöfe (where the castle had been), Sienhachenbach, Schmidthachenbach, Mittelreidenbach, Oberreidenbach, Weierbach, Dickesbach, Zaubach, Kefersheim, Wickenhof, Ehlenbach, Wieselbach, Kirchenbollenbach, Mittelbollenbach and Nahbollenbach. In Prussian times, the "Amtshaus" (administrative centre for the "Amt") was built. With the new lords, a gradual economic upswing set in, reaching a peak in the latter half of the 19th century. Many urban-style houses and the Gothic Revival Catholic church, upon whose consecration in 1892 the simultaneum ended, still bear witness to the wealth at that time.