Princess Alexia of Greece and Denmark
Princess Alexia of Greece and Denmark( born 10 July 1965) is the eldest child of Constantine II and Anne- Marie of Denmark, who were king and queen of Greece from 1964 until the abolition of the monarchy in 1973.
Prince Nikolaos of Greece and Denmark
Prince Nikolaos of Greece and Denmark( born 1 October 1969) is the third child of Constantine II and Anne- Marie of Denmark, who were the last King and Queen of Greece, reigning from 1964 to 1973.
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 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.
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.
Prince Achileas-Andreas of Greece and Denmark
Prince Achileas- Andreas of Greece and Denmark( born 12 August 2000) is a member of the Greek royal family.
He is the second son and third child of Crown Prince Pavlos of Greece and Marie- Chantal Miller.
His paternal grandparents are Constantine II of Greece and Anne- Marie of Denmark, who were the last King and Queen of the Hellenes.
He is currently third in the line of succession to the former Greek throne.
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 Tatiana of Greece and Denmark
Princess Tatiana of Greece and Denmark( born Tatiana Ellinka Blatnik, 28 August 1980) is the wife of Prince Nikolaos, son of Constantine II, who reigned as King of Greece until the monarchy was abolished in 1973.
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: What is the place of birth of Princess Irene, Duchess Of Aosta's father?
Answer: Athens