Duchess of Oldenburg is a very attractive early-season apple, originating from Russia in the early 18th century. It is primarily used as a cooking apple.
As might be expected, Duchess of Oldenburg is a very hardy apple tree. Although not a commercial variety, it became popular across northern Europe and was introduced to North America in the early 19th century.
Duchess of Oldenburg is possibly an ancestor of the well-known Northern Spy apple of North America.