an Entity references as follows:
The Gastein Convention (German: Gasteiner Konvention), also called the Convention of Badgastein, was a treaty signed at Bad Gastein in Austria on 14 August 1865. It embodied agreements between the two principal powers of the German Confederation, Prussia and Austria, over the governing of the 'Elbe Duchies' of Schleswig, Holstein and Saxe-Lauenburg.