I. Territory

The territory of Oldenburg was absorbed in 1946 into the Land of Lower Saxony, but within the structures of the Protestant and Catholic churches, it retains more or less the boundaries of the duchy of Oldenburg determined by the Congress of Vienna (Vienna, Congress of), comprising the administrative districts of Friesland, Wesermarsch, Ammerland, Oldenburg, Cloppenburg, and Vechta, and t…