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.
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.
Princess Maria-Olympia of Greece and Denmark
Princess Maria- Olympia of Greece and Denmark( born 25 July 1996) is an American fashion model, socialite and member of the Greek royal family.
She is the oldest child and only daughter of Pavlos, Crown Prince of Greece and his wife, Marie- Chantal Miller.
Her paternal grandparents are Constantine II of Greece and Anne- Marie of Denmark, who were the last King and Queen of the Hellenes, while her maternal grandfather is duty free entrepreneur Robert Warren Miller.
She is currently sixth in the line of succession to the former throne of Greece, after her father and brothers.
Princess Maria Pia of Bourbon-Parma
Princess Maria Pia of Bourbon- Parma( née Princess Maria Pia of Savoy; born 24 September 1934) is the eldest daughter of Umberto II of Italy and Marie- José of Belgium.
She is the older sister of Princess Maria Gabriella of Savoy, Vittorio Emanuele, Prince of Naples, and Princess Maria Beatrice of Savoy.
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 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 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 Maria of Greece and Denmark
Princess Maria of Greece and Denmark  (3 March 1876 – 14 December 1940) was a daughter of King George I of Greece and his wife Grand Duchess Olga Constantinovna of Russia.
She was a sister of King Constantine I of Greece and a first cousin of Tsar Nicholas II of Russia.
Born as a princess of Greece and Denmark, she was educated in Athens by private tutors.
Her father instilled in her a great love for Greece and throughout her life, she remained a fervent patriot.
She married Grand Duke George Mikhailovich of Russia, her first cousin once removed, who courted her for five years.
The wedding took place in 1900 in Corfu.
The couple settled in St. Petersburg and they had two daughters: Princesses Nina (1901 -1974) and Xenia of Russia (1903 -1965).
Grand Duke George Mikhailovich had a house built for her in Crimea and he was a devoted father and husband, but the marriage was unhappy.
Princess Maria, known upon her marriage as Grand Duchess Maria Georgievna of Russia, neither get to love her husband nor her adopted country.
Longing for her native Greece, she never adapted to live in Russia.
Over the years, she became estranged from her husband taking any opportunity to spend time abroad.
At the outbreak of World War I, she was vacationing in England with her daughters and chose not to return to Russia.
During the conflict, she was a patron of three military hospitals in Harrogate, which she financed generously.
Her husband was trapped in Russia after the revolution and he was shot by the Bolsheviks with several other Romanov relatives in January 1919.
In her widowhood, deprived of her Russian income, Princess Maria faced serious financial difficulties.
She returned to live in Greece with her daughters in 1920.
There, she began a relationship with Admiral Perikles Ioannidis, who had been the commander of the ship that she took at her return to Athens.
They were married in 1922.
The proclamation of the Second Hellenic Republic in 1924, sent her into exile.
The princess returned to live in Britain for a couple of years and she settled in Rome in 1926 with her second husband.
She lived in Italy for over a decade until the outbreak of the Greco-Italian War in 1940 forced her to return to her native Greece.
She was in poor health and was cared for by her nephew King Paul of Greece and his wife Frederica.
She died, as the Greek royal family was about to leave for exile.
She left a book of memoirs, published posthumously by her grandchildren with the title "A Romanov Diary".
Princess Xenia Georgievna of Russia
Princess Xenia Georgievna of Russia( 22 August 1903, Mikhailovskoe, Russia – 17 September 1965, Glen Cove, New York) was the younger daughter of Grand Duke George Mihailovich of Russia and Princess Maria Georgievna of Greece and Denmark.
She was a granddaughter of George I of Greece and first cousin of the brothers King Alexander I of Greece, King George II of Greece, King Paul I of Greece and their sister Queen Helen, Queen Mother of Romania and also of Prince Philip, Duke of Edinburgh.
George I of Greece
George I (Greek:
Γεώργιος Α΄, Geórgios I; 24 December 1845 – 18 March 1913) was King of Greece from 1863 until his assassination in 1913.
Originally a Danish prince, he was born in Copenhagen, and seemed destined for a career in the Royal Danish Navy.
He was only 17 years old when he was elected king by the Greek National Assembly, which had deposed the unpopular former king Otto.
His nomination was both suggested and supported by the Great Powers: the United Kingdom of Great Britain and Ireland, the Second French Empire and the Russian Empire.
He married the Russian grand duchess Olga Constantinovna of Russia in 1867, and became the first monarch of a new Greek dynasty.
Two of his sisters, Alexandra and Dagmar, married into the British and Russian royal families.
King Edward VII and Tsar Alexander III were his brothers-in-law, and King George V, Tsar Nicholas II, King Christian X of Denmark and King Haakon VII of Norway were his nephews.
George's reign of almost 50 years (the longest in modern Greek history) was characterized by territorial gains as Greece established its place in pre-World War
I Europe.
Britain ceded the Ionian Islands peacefully in 1864, while Thessaly was annexed from the Ottoman Empire after the Russo-Turkish War (1877–1878).
Greece was not always successful in its territorial ambitions; it was defeated in the Greco-Turkish War (1897).
During the First Balkan War, after Greek troops had captured much of Greek Macedonia, George was assassinated in Thessaloniki.
Compared with his own long tenure, the reigns of his successors Constantine, Alexander, and George II proved short and insecure.

Question: What is the date of birth of Princess Maria Of Greece And Denmark's father?
Answer: 24 December 1845