King Constantine II's funeral on Monday 16 January will be a private service at the Metropolitan Cathedral of Athens, and the former head of state will be buried at Tatoi palace cemetary, it has been confirmed.
Times of the service, the burial and the lying in repose at Church will be announced at a later date, and meanwhile, tributes to King Constantine have been pouring in from royal families around the world.
WATCH: King Charles pays tribute to the late Queen in Christmas speech
Sharing a black and white image on their official Instagram account, the Danish royal family said: "It is with great sadness that Her Majesty The Queen and the royal family have received notification that His Majesty King Constantine II of Greece has passed away on Tuesday evening.
"The thoughts of the royal family at this moment go out to Her Majesty Queen Anne-Marie and the entire Greek family."
LATEST: Princess Kate pictured looking sombre after royal family death and Prince Harry bombshells
Queen Margrethe pictured with King Constantine and Prince Henrik in 1983
Also paying tribute were Romania's royal family. An official statement read: "The Royal Family of Romania learned with much distress of the passing of His Majesty King Constantine II of the Hellenes.
"King Constantine was all his life close to the Royal Family of Romania, to Queen-Mother Helen, his father's sister, as well as to King Michael and Queen Anne. Custodian of the Crown Margareta, as well as Princesses Helena, Irina, Sophie and Marie, have known their uncle since their early childhood.
"For more than seven decades, the two families always met in Greece, and then in Switzerland, in Great Britain, as well as in various European capitals, at public or private events.
King Constantine attended Margareta of Romania's wedding in 1996
"King Constantine was Her Majesty Margareta's godfather and also godfather at the Orthodox wedding of the Custodian of the Crown and Prince Radu, in Lausanne, in 1996. King Constantine, like all his family, was always faithfully present at all the important events, be they happy or sad, of the Royal Family of Romania. May God rest him in peace!"
Meanwhile, Serbia's Crown Prince Alexander wrote: "With great sadness, Princess Katarina and I received the news that yesterday, she was 10. January 2023. year, in Athens our dear cousin, godfather and friend, NJ. V. King Constantine II of Greece."
He added: "In these most difficult moments, the Royal Family of Serbia shares the sorrow and pain over the death of His Majesty and sends prayers to the Lord to remember the late King in his mercy. The departure of NJ. V. King Constantine II hurts a lot, he will be greatly missed by everyone, but the memory of him will, with great love and respect, be cherished forever."
NEW: Prince Harry recalls snapping at Meghan Markle - 'I was disproportionately angry'
Constantine, who was 82 when he passed away, had been suffering from ill health for a number of years and was being treated at the private Hygeia Hospital in Athens.
Constantine acceded to the Greek throne in 1964 following the death of his father, King Paul. However, he would rule for less than a decade after a military junta abolished the monarchy.
Two referendums were held following the abolition, a disputed one in 1973 before a second one in 1974, with both returning results in favour of abolition.
The father-of-three lived in exile for many years in Hampstead Garden Suburb, before eventually returning to his native country in 2010.