It looks like the PLF symposium held in Copenhagen was a great success with Royal attendees.
This report from Royal Central.
Her Majesty Queen Margrethe of Denmark and her younger sister, Queen Anne-Marie of Greece made a rare joint appearance together yesterday at the University of Copenhagen for the “To Greece with Love” symposium.
The two-day conference, attended by people from as far away as Texas, USA, was organised around the British travel writer and freedom fighter in Greece, Patrick Leigh Fermor. Their Majesties heard various lectures, including one from Patrick Leigh Fermor’s biographer, Artemis Cooper.
The Queen of Denmark had met Artemis Cooper in 2017 during a lunch in the United Kingdom.
Queen Margrethe, who has reportedly read all of Fermor’s travel books, and Queen Anne-Marie were private guests at the event and were welcomed by Charles Lock, an English professor at the University of Copenhagen upon their arrival.
Patrick Leigh Fermor died in 2011 and was considered as one of Britain’s greatest travel writers during his lifetime. He played a prominent role during the Second World War in the Cretan resistance in Greece.
Queen Anne-Marie (born Princess Anne-Marie of Denmark) is six years younger than Queen Margrethe. They have another sister, Princess Beneditke, who was born in 1944. Anne-Marie was 13 when she first met her future husband, the then Prince Constantine of Greece and Denmark in 1959. Their engagement was announced in July 1964 – just a few months after Constantine had become King of Greece. They married on 18 September 1964 and have five children: Princess Alexia, Crown Prince Pavlos, Prince Nikolaos, Princess Theodora and Prince Philippos.
The family was forced into exile in Greece in the late 1960s when a military junta took over. They first lived in Italy before relocating to England. They were not permitted to return to Greece until 1981 when they were allowed to enter the country for a few hours to attend the funeral of Constantine’s mother, Queen Frederika.
King Constantine, Queen Anne-Marie, their son Prince Nikolaos and his wife, Princess Tatiana now reside in Greece.
Patrick Leigh Fermor 
Dear Sir, please note that Greece is a Republic not a kingdom. It has not recognised the existence of a Greek Royal Family since 1974. These individuals have continued to refer to themselves as Royals but they do that of their own volition and without a country or subjects to belong to. So to correct you, you are speaking of the Queen of Denmark and her younger sister Anne Marie. It is an insult to Greece and its citizens to use titles which the Greek government does not recognise.
Noted, but please direct your comments to the author of the article – see link near start. Thank you.
Just how many Greek citizens are insulted as Maria here claims? As for upsetting the Greek government, or any government, by using titles which they do not recognise, I wouldn’t worry about that at all.