Constantine II (2 June 1940 – 10 January 2023) was the last King of Greece, reigning from 1964 to 1974. After the 1974 referendum and proclamation of the Republic, the King and his family resided in the United Kingdom until 2013.

As the only son of King Paul I and Queen Frederica, Constantine II was proclaimed King of the Hellenes on 6 March 1964 at the age of 24, succeeding his father King Paul I, the first cousin of HRH Prince Philip of Greece, the Duke of Edinburgh.

He served in all three branches of the Hellenic Armed Forces and attended the National and Kapodistrian University of Athens Law School.

He had two sisters, Queen Sofía of Spain (tenure: 1975–2014) and Princess Irene.

In 1964, he married Princess Anne-Marie, the youngest daughter of King Frederik IX of Denmark, with whom he had five children: Princess Alexia, Crown Prince Pavlos, Prince Nikolaos, Princess Theodora, and Prince Philippos.

He was an Olympic sailing champion, winning gold at the Rome 1960 Olympic Games, and served as both President of the Hellenic Olympic Committee and an honorary member of the International Olympic Committee.

In 2013, King Constantine II returned to permanently reside in Greece. He passed away in the city of his birth, Athens, on 10 January 2023 and was buried privately in the Royal Cemetery at Tatoi.

Defined by an absolute respect for the Greek people and by a deeply-held love for his country, King Constantine II was ever faithful and resolute in his service to Greece, employing all means at his disposal throughout his life to this end.