Landgrave Carl of Hesse-Kassel (1744–1836) was married in 1766 to Princess Louise of Denmark (1750–1831), daughter of King Frederik V of Denmark of the Oldenburg line. He was governor and commanding general in the duchies of Schleswig-Holstein with winter residence at Gottorp Castle in Schleswig city and a summer residence at the southestern situated country estate Louisenlund. The couple became, among others, parents of Princess Marie, married to King Frederik VI of Denmark, Princess Juliane, abbess of Itzehoe Monastery, and Princess Louise, married to Duke Wilhelm of Schleswig-Holstein-Sonderburg-Glücksburg. The Landgrave couple became parents of, among others, Duke Carl of Glücksburg, Duke Friedrich of Glücksburg, Duchess Friederike of Anhalt-Bernburg, and King Christian IX of Denmark. The couple were thus the grandparents of this Danish king and two Dukes of Glücksburg and they embodies the connection between the Danish Royal House and the Glücksburg family citizens of Glück, as well as the connection between the Oldenburg and the Glücksburg lines.

Provenance: ”The Historical Collection of Four Princesses From the Cavalier House of Glücksburg Castle”. The cultural heritage after the sisters, Her Highness Princess Elisabeth of Ysenburg and Büdingen, née Princess of Schleswig-Holstein-Sonderburg-Glücksburg (1945–2024), Her Highness Princess Irene of Schleswig-Holstein-Sonderburg-Glücksburg (b. 1946), Her Highness Princess Margaretha of Schleswig-Holstein-Sonderburg-Glücksburg (b. 1948), and Her Highness Princess Sibylla Ursula of Schleswig-Holstein-Sonderburg-Glücksburg (b. 1955). Online auction no. 2545 at Bruun Rasmussen Arts Auctioneers in Lyngby, 3 November, 2025.