Albert II of Belgium in the context of "Elisabeth of Bavaria, Queen of the Belgians"

Princess Märtha of Sweden (Märtha Sofia Lovisa Dagmar Thyra; 28 March 1901 – 5 April 1954) was Crown Princess of Norway as the spouse of the future King Olav V from 1929 until her death in 1954. As Olav only became king in 1957, Märtha never became Queen of Norway. Her son, Harald V, is the current king of Norway. Princess Märtha was also an elder sister of Queen Astrid of Belgium and a maternal aunt of Grand Duchess Joséphine-Charlotte of Luxembourg and Kings Baudouin and Albert II of Belgium.

In 1940, Crown Princess Märtha and her family were immersed in World War II as Germany invaded Norway. After escaping to her home country of Sweden, and then being evacuated to America by President Franklin D. Roosevelt, she effectively advocated for Norway and did fundraising until the end of the war. In 1942, King Haakon VII of Norway, Märtha's father-in-law, invested her as a Dame Grand Cross of the Royal Norwegian Order of Saint Olav.

The monarchy of Belgium is the constitutional and hereditary institution of the monarchical head of state of the Kingdom of Belgium. As a popular monarchy, the Belgian monarch uses the title king/queen of the Belgians and serves as the country's head of state and commander-in-chief of the Belgian Armed Forces.

There have been seven Belgian monarchs since independence in 1830. The incumbent, Philippe, ascended the throne on 21 July 2013, following the abdication of his father Albert II.

Philippe or Filip (born 15 April 1960) is King of the Belgians.

Philippe is the eldest child of King Albert II and Queen Paola. He succeeded his father upon the former's abdication for health reasons on 21 July 2013. He married Mathilde d'Udekem d'Acoz in 1999, with whom he has four children. Their eldest child, Princess Elisabeth, is first in the line of succession.

Baudouin (US: /boʊˈdwæ̃/; 7 September 1930 – 31 July 1993) was King of the Belgians from 17 July 1951 until his death in 1993. He was the last Belgian king to be sovereign of the Congo, before it became independent in 1960 and became the Democratic Republic of the Congo (known from 1971 to 1997 as Zaire).

Baudouin was the elder son of King Leopold III (1901–1983) and his first wife, Princess Astrid of Sweden (1905–1935). Because he and his wife, Queen Fabiola, had no children, at Baudouin's death the crown passed to his younger brother, King Albert II.

Astrid of Sweden (Astrid Sofia Lovisa Thyra; 17 November 1905 – 29 August 1935) was a member of the Swedish House of Bernadotte and later became Queen of the Belgians as the first wife of King Leopold III. Following her marriage to Leopold in November 1926, she assumed the title of Duchess of Brabant. Astrid held the position of Queen of the Belgians from 23 February 1934 until her death in 1935. Known for her charitable efforts, she focused particularly on causes related to women and children.

Astrid and Leopold had three children. Their daughter, Joséphine-Charlotte, later became the Grand Duchess Consort of Luxembourg, while their sons both ascended the throne as King of the Belgians. Their son King Albert II named his first daughter, Princess Astrid of Belgium, after his mother. Queen Astrid was the sister of Crown Princess Märtha of Norway (the wife of the future King Olav V).

Princess Joséphine-Charlotte of Belgium (11 October 1927 – 10 January 2005) was the Grand Duchess of Luxembourg as the wife of Grand Duke Jean. She was the first child of King Leopold III of Belgium, and sister of the late King Baudouin and former King Albert II and aunt of King Philippe. She was also the maternal first cousin of King Harald V of Norway, maternal second cousin of former Queen Margrethe II of Denmark, and a paternal third cousin of late Queen Elizabeth II of the United Kingdom.

Paola Margherita Maria-Antonia Consiglia dei Principi Ruffo di Calabria (born 11 September 1937) is a member of the Belgian royal family who was Queen of the Belgians during the reign of her husband, King Albert II, from 9 August 1993 to 21 July 2013.