Alexandra of Denmark

Constantine I (1868 to 1923) was King of the Hellenes from 1913 to 1917 and again from 1920 to 1922, the eldest son of George I and Olga Constantinovna of Russia. He commanded Greek forces in the Balkan Wars, when Greece nearly doubled in size, which made him immensely popular at his accession. His insistence on neutrality in the First World War brought him into open conflict with his prime minister Eleftherios Venizelos, splitting the country in the National Schism and forcing him from the throne in 1917. Restored in 1920, he lost the throne again after the defeat in Asia Minor and died in exile in Palermo. He married Sophia of Prussia and was the father of three Greek kings.

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.

Christian X (1870 to 1947) was King of Denmark from 1912 to 1947 and King of Iceland from 1918 to 1944, the eldest son of Frederik VIII and Louise of Sweden. His reign opened with constitutional conflict, including the Easter Crisis of 1920 in which his dismissal of the elected government nearly cost the monarchy its position, and closed with the German occupation of Denmark from 1940 to 1945, during which his daily rides through Copenhagen on horseback became a symbol of national endurance. He married Alexandrine of Mecklenburg-Schwerin in 1898 and was the father of Frederik IX of Denmark. His brother reigned in Norway as Haakon VII.

George II (1890 to 1947) was King of the Hellenes from 1922 to 1924 and again from 1935 until his death, the eldest son of Constantine I and Sophia of Prussia. He came to the throne after the Asia Minor defeat, was pushed aside within two years when Greece declared a republic, and lived in exile in Romania and Britain for eleven years before a plebiscite restored the monarchy in 1935. His second reign saw the Metaxas government, the Italian invasion of 1940 and the German occupation, through which he led the Greek government in exile from Cairo and London. He returned to Greece in 1946 and died the following year, succeeded by his brother Paul.

Alexander (1893 to 1920) was King of the Hellenes from 1917 to 1920, the second son of Constantine I and Sophia of Prussia. He was placed on the throne by the Allies and the Venizelos government after his father and elder brother were forced out, and ruled as a largely powerless monarch while real authority rested with his prime minister, who kept him from political affairs and from contact with his exiled family. During his short reign Greece fought alongside the Allies and made large territorial gains in Thrace and Asia Minor. His marriage in 1919 to Aspasia Manos, a Greek commoner, was not initially recognised. He died in 1920 and was succeeded by his father.

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.

Paul (1901 to 1964) was King of the Hellenes from 1947 until his death, the youngest son of Constantine I and Sophia of Prussia. He trained as a naval officer, spent long years in exile during the Greek republic, and served with the Greek forces in the Second World War before returning home. He succeeded his brother George II in the middle of the Greek Civil War, and his reign then covered the post-war reconstruction years, Greece's entry into NATO and the Cyprus crisis. He married Frederica of Hanover, a great-granddaughter of Christian IX through Thyra of Denmark, in 1938; their children were Sofía, later Queen of Spain, Constantine II and Irene.

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 Benedikte of Denmark (born 1944) is the second daughter of Frederik IX and Ingrid of Sweden and the younger sister of Queen Margrethe II. In 1968 she married Richard, Prince of Sayn-Wittgenstein-Berleburg, and for many years divided her life between Germany and Denmark, retaining her Danish royal duties on the condition that her children were raised in Denmark for part of the year. She has carried out an unusually long record of official engagements for the Danish crown and is best known publicly for her lifelong involvement with equestrian sport, serving in senior roles in Danish and international riding organisations, as well as with the Danish Girl Guides and a wide range of charities.