How did Napoleon III’s proposals affect the London Conference of 1864?

At the London Conference of 1864, Napoleon III’s proposal to consult the wishes of the local populations regarding their political future significantly influenced the proceedings.

Otto von Bismarck adapted this suggestion into a broader proposal to separate Holstein and southern Schleswig from Denmark. Under this modified plan, the populations would determine the new frontier line and decide between independence or union with Prussia. This marked the first time that the possibility of union with Prussia had been proposed in an international forum. Although Bismarck could not publicly advocate for this outcome without violating his alliance with Austria, he began working toward that end privately, effectively shifting the conference's focus away from the principle of Danish integrity.1