Question: Princess Maria-Olympia is the only daughter of the eldest son and second child of Constantine II, who was the last king of Greece from 1964 until when?

Related documents: [0]  [DOC] Princess Maria-Olympia of Greece and Denmark (born 25 July 1996 in New York City) is the oldest child and only daughter of Pavlos, Crown Prince of Greece and Marie-Chantal, Crown Princess of Greece. Her paternal grandparents are Constantine II and Anne-Marie of Denmark, who were the last King and Queen of the Hellenes. [END] 
[1]  [DOC] Pavlos, Crown Prince of Greece, {'1': ", '2': ", '3': 'RE', '4': "} (Greek: Παύλος ; born 20 May 1967) is the eldest son and second child of Constantine II, the last King of Greece from 1964 to 1973 and his wife, Anne-Marie of Denmark. Pavlos was heir apparent to the throne of Greece and was its crown prince from birth, remaining so during his father's reign until the monarchy's abolition. [END]  
Answer: 1973
1973