Schloss Glücksburg holds an important place in the history of Schleswig-Holstein and Scandinavia on account of the fact that it was a royal residence for a time and also the administrative seat of the dukedom of Glücksburg.
The builder, Duke Johann the Younger, was the brother of the King of Denmark, brother-in-law of the Elector of Saxony and, through many of his 23 children, became father-in-law of several German sovereigns. He was high in the German Emperor’s favour.
Duke Hans von Schleswig-Holstein-Sonderburg, although a son of the Danish King Christian III, had no part in matters of State, instead concentrating on his farming operations.
He is the progenitor of the various branches of the Sonderburg House of Princes, including those of Augustenburg, Glücksburg, Plön and Beck.
Between 1622 and 1779 five generations of Dukes of Glücksburg resided in the castle. The last Duke of the older Glücksburg line died in 1779. After the death of his widow, King Friedrich VI of Denmark awarded the title to Duke Wilhelm of Schleswig-Holstein-Sonderburg-Beck on 6 July 1825, along with the castle complex. Wilhelm, who grew up in Prussia and Denmark, was a direct descendant of Johann the Younger. He assisted the Danish King during the Congress of Vienna. He married Louise Caroline, whose father was governor of the dukedoms of Landgrave Karl von Hessen. Among their 10 children were the future King Christian IX of Denmark and Duke Friedrich, from whom the current Head of the House Schleswig-Holstein is descended.
After 1854 the castle served as the summer residence for King Friedrich VII, who died here on 15 November 1863. In 1864/1865 Prussian troops used the castle as quarters and as a military hospital. After the ceding by Denmark of the dukedom Schleswig-Holstein to the Prussian crown, King Wilhelm gave the castle back to the family. Duke Karl, the Head of the House Schleswig-Holstein-Sonderburg-Glücksburg at the time, made it his home in 1871. Karl was the brother of Christian IX who, in 1846, withdrew from Danish State service because of his opposition to the policy of the "Eiderdänen" who called for a total merger of Schleswig into Denmark.
The last German Empress, Auguste Victoria, a descendant of the House of Schleswig-Holstein-Sonderburg-Augustenburg, stayed in Glücksburg frequently. Her sister Caroline Mathilde married Duke Friedrich Ferdinand (1855-1934).
Auguste Victoria is the great-grand-Aunt of Prince Christoph and Caroline Mathilde is his great-grandmother.