Due to the complicated nature of succession, Frederick and his older brother, Christian August II, Duke of Schleswig-Holstein-Sonderburg-Ausgustenburg, both saw themselves as rightful heirs to the duchies, as well as the Kingdom of Denmark.

The two shared a goal of achieving a united Schleswig-Holstein belonging to the German Confederation, complete with a liberal constitution.

Upon Schleswig-Holstein's capitulation to Denmark, Frederick went into exile (1851) and for a time in 1852 was documented as residing in Devon, England.

In 1864, after the Kingdom of Prussia and the German Confederation had, under the Austrian Empire's leadership, defeated Denmark in the Second Schleswig War, Frederick was reassigned the title of "Prince of Noer" by decree of Emperor Franz Joseph I of Austria.

Eight years after the death of her first husband, the Princess married Count Alfred von Waldersee, a General who was later created Field Marshal.