George II of Greece

Louise of Hesse-Kassel (1817 to 1898) was Queen of Denmark as the wife of Christian IX and the matriarch of the modern House of Glücksburg. Born in Kassel, she was a niece of Christian VIII of Denmark, and it was partly through her own descent that her husband's claim to the Danish succession was strengthened. She married Christian in 1842 and had six children: Frederik VIII, Alexandra, George I of Greece, Dagmar, Thyra and Valdemar. A gifted musician and a determined organiser of her children's futures, she did more than anyone to arrange the marriages that carried her family into the British, Russian, Greek and later Norwegian royal houses.

Christian IX (1818 to 1906) was King of Denmark from 1863 until his death, and the ancestor from whom every later member of the House of Glücksburg descends. Born at Gottorp Castle in Schleswig into a cadet branch of the House of Oldenburg, he was named heir to the childless Frederik VII and came to the throne in a year of crisis, losing Schleswig and Holstein in the war of 1864 and later accepting the parliamentary reforms that shaped modern Danish politics. With his wife Louise of Hesse-Kassel he had six children whose marriages earned him the nickname father-in-law of Europe: Frederik VIII of Denmark, Alexandra, queen consort of the United Kingdom, George I of Greece, Dagmar, who became Empress Maria Feodorovna of Russia, Thyra, and Valdemar.

Frederik VIII (1843 to 1912) was King of Denmark from 1906 to 1912, the eldest son of Christian IX and Louise of Hesse-Kassel. He waited more than forty years as crown prince, during which he was more sympathetic than his father to the liberal parliamentary movement, and his short reign was marked by a conciliatory tone towards the Danish government and a cautious reform of the relationship with Iceland. He married Louise of Sweden in 1869. Two of their sons became kings: Christian X of Denmark and Prince Carl, who was elected King of Norway in 1905 as Haakon VII, making Frederik VIII the father of two reigning Scandinavian dynasties.

Alexandra of Denmark (1844 to 1925) was Queen consort of the United Kingdom and Empress of India as the wife of Edward VII. The eldest daughter of Christian IX and Louise of Hesse-Kassel, she grew up in modest circumstances in Copenhagen before her marriage in 1863 made her Princess of Wales, a role she held for 38 years, longer than anyone before her. Admired for her style and her charitable work, she founded the Imperial Military Nursing Service that bears her name and gave her name to Alexandra Rose Day. Her sister Dagmar became Empress of Russia, her brother became George I of Greece, and her daughter Maud became Queen of Norway.

Nicholas II (1868 to 1918) was the last Emperor of Russia, reigning from 1894 until his abdication in March 1917. He was the eldest son of Alexander III and of Maria Feodorovna, the Danish-born daughter of Christian IX, which made him a grandson of the founder of the House of Glücksburg and a first cousin of both George V of the United Kingdom and Christian X of Denmark, whom he closely resembled. His reign saw rapid industrial growth alongside the defeat of the Russo-Japanese War, the revolution of 1905 and the creation of the Duma, and finally the strains of the First World War, which brought the three-century Romanov monarchy to an end. He died in 1918.

Maud of Wales (1869 to 1938) was the first queen of independent Norway, wife of Haakon VII. The youngest daughter of Edward VII and Alexandra of Denmark, she was also a granddaughter of Christian IX, which means both she and her husband descended from the founder of the House of Glücksburg. She married her first cousin Prince Carl of Denmark in 1896 and moved to Norway when he accepted the throne in 1905. Keenly interested in winter sports, music and fashion, she kept close ties to Britain while supporting Norwegian charities and the arts, and her wardrobe is now a studied collection at the National Museum in Oslo. She was the mother of Olav V.

Frederik IX (1899 to 1972) was King of Denmark from 1947 until his death, the elder son of Christian X and Alexandrine of Mecklenburg-Schwerin. A career naval officer before his accession, he was an enthusiastic sailor and an accomplished amateur conductor, and he cultivated a relaxed, approachable style that suited post-war Denmark. The defining act of his reign was the constitutional change of 1953, which allowed female succession and so made his eldest daughter his heir. He married Ingrid of Sweden in 1935, and their three daughters were Margrethe II of Denmark, Benedikte, and Anne-Marie, who became Queen of the Hellenes.

Queen Sofía of Spain (born 1938) was Queen consort of Spain from 1975 to 2014 and is the eldest child of Paul of Greece and Frederica of Hanover. Born in Athens as a princess of Greece and Denmark, she was educated in Germany and Greece, trained as a paediatric nurse, and took part in the Greek sailing team's preparations for the 1960 Olympics alongside her brother Constantine II. She married Juan Carlos of Spain in Athens in 1962, converting from Orthodoxy to Catholicism, and became queen when he acceded on the death of Franco in 1975. Widely respected for her work on disability, music education and social welfare, she is the mother of King Felipe VI of Spain.

Constantine II (1940 to 2023) was the last King of the Hellenes, reigning from 1964 to 1973. The only son of Paul and Frederica of Hanover, he spent his early childhood in wartime exile and won an Olympic gold medal for Greece in Dragon class sailing at the Rome Games in 1960. He came to the throne at twenty-three; within three years the colonels' coup of April 1967 had stripped him of power, and after a failed counter-move that December he left the country. The junta abolished the monarchy, and a referendum in 1974 confirmed the republic. He lived mainly in London for decades before settling again in Greece, and remained a member of the International Olympic Committee. He married Anne-Marie of Denmark in 1964.

Margrethe II (born 1940) reigned as Queen of Denmark from 1972 until her abdication on 14 January 2024, becoming Europe's longest-serving head of state before she stood down. The eldest daughter of Frederik IX and Ingrid of Sweden, she became heir only because the constitution was changed in 1953 to allow female succession. She trained as an archaeologist, taking part in excavations in Egypt and Italy, and built a parallel career as an artist: she designed stage sets and costumes, and illustrated the Danish edition of The Lord of the Rings under the name Ingahild Grathmer. She married Henri de Laborde de Monpezat in 1967 and is the mother of King Frederik X and Prince Joachim.

Princess Alexia of Greece and Denmark (born 1965) is the eldest child of Constantine II and Anne-Marie of Denmark. Born at Mon Repos on Corfu, the same house as her kinsman Prince Philip, she was two when her family left Greece, and she grew up in Rome and London. She studied art history and later trained to work with children with special educational needs, teaching in that field. In 1999 she married Carlos Morales Quintana, an architect, and the couple lived for many years in Lanzarote in the Canary Islands and later in London. She is the sister of Crown Prince Pavlos, Nikolaos, Theodora and Philippos.