Richard Brandram
Richard Campbell Andrew Brandram, MC( 5 August 1911 – 28 March 1994) was a Major in the British Army who married Princess Katherine of Greece and Denmark in 1947, which united him with most of the royal families in Europe.
Princess Katherine of Greece and Denmark
Princess Katherine of Greece and Denmark (4 May 1913 – 2 October 2007), styled in the UK as Lady Katherine Brandram from 1947 till her death, was the third daughter and youngest child of King Constantine I of Greece and Sophia of Prussia.
Princess Irene, Duchess of Aosta
Princess Irene of Greece and Denmark( 13 February 1904 – 15 April 1974) was the fifth child and second daughter of Constantine I of Greece and his wife, the former Princess Sophie of Prussia.
She was a member of the royal families of Greece and Italy.
From 1941 to 1943 she was also officially Queen Consort of Croatia.
Princess Margarita of Greece and Denmark
Princess Margarita of Greece and Denmark( 18 April 1905 – 24 April 1981) was the eldest child and daughter of Prince Andrew of Greece and Denmark and Princess Alice of Battenberg.
She was the first great- great- grandchild of Queen Victoria, and the eldest sister of Prince Philip, Duke of Edinburgh.
Princess Elizabeth of Greece and Denmark
Princess Elisabeth of Greece and Denmark( 24 May 1904 – 11 January 1955) was the middle daughter of Prince Nicholas of Greece and Grand Duchess Elena Vladimirovna of Russia.
Princess Eugénie of Greece and Denmark
Princess Eugénie of Greece and Denmark( 10 February 1910 – 13 February 1989) was the youngest child and only daughter of Prince George of Greece and Denmark and his wife, Princess Marie Bonaparte, daughter of Marie- Félix Blanc and Prince Roland Bonaparte, a great- nephew of Napoleon I.
Her father was the second son of George I of Greece and Olga Constantinovna of Russia.
As a cousin of the bridegroom, she was a leading guest at the 1947 wedding of Princess Elizabeth and Philip, Duke of Edinburgh.
She authored" Le Tsarevitch, Enfant Martyr", a biography of Aleksey Nikolaevich, Tsarevich of Russia, written in French, which was published in 1990.
Princess Anastasia of Greece and Denmark
Princess Anastasia of Greece and Denmark ("née" Nonie May Stewart; 20 January 1878 – 29 August 1923) was an American-born heiress and member of the Greek Royal Family.
She was married to Prince Christopher of Greece and Denmark, the youngest child of King George I of Greece and his consort, Grand Duchess Olga Constantinovna of Russia, but was created a princess "suo jure".
Princess Theodora of Greece and Denmark (1906–1969)
Princess Theodora of Greece and Denmark( 30 May 1906 – 16 October 1969) was the second child and daughter of Prince Andrew of Greece and Denmark and Princess Alice of Battenberg, and the second eldest sister of Prince Philip, Duke of Edinburgh.
Constantine I of Greece
Constantine I ("Konstantínos I"; – 11 January 1923) was King of Greece from 1913 to 1917 and from 1920 to 1922.
He was commander-in-chief of the Hellenic Army during the unsuccessful Greco-Turkish War of 1897 and led the Greek forces during the successful Balkan Wars of 1912–1913, in which Greece expanded to include Thessaloniki, doubling in area and population.
He succeeded to the throne of Greece on 18 March 1913, following his father's assassination.
His disagreement with Eleftherios Venizelos over whether Greece should enter World War
I led to the National Schism.
Constantine forced Venizelos to resign twice, but in 1917 he left Greece, after threats by the Entente forces to bombard Athens; his second son, Alexander, became king.
After Alexander's death, Venizelos' defeat in the 1920 legislative elections, and a plebiscite in favor of his return, Constantine was reinstated.
He abdicated the throne for the second and last time in 1922, when Greece lost the Greco-Turkish War of 1919–1922, and was succeeded by his eldest son, George II.
Constantine died in exile four months later, in Sicily.
Princess Irene of Greece and Denmark
Princess Irene of Greece and Denmark( born 11 May 1942) is the youngest child and second daughter of King Paul of Greece and his wife Princess Frederika of Hanover.
She is the younger sister of Queen Sofía of Spain and of the deposed King Constantine II of Greece and maternal aunt of Felipe VI of Spain.

Question: When did Princess Katherine Of Greece And Denmark's father die?
Answer: 11 January 1923