Linked to the German House of Glucksberg which has connections with royalty throughout Europe, Constantine II was the only son of King Paul and Queen Frederica of Greece.

Royals from Europe, including Britain's Princess Anne, and Spain's King Felipe and Queen Letizia attended the Orthodox Christian service at the Metropolitan Cathedral in central Athens. Royals from Denmark, Norway, Sweden, the Netherlands, Belgium, Luxembourg and Monaco were also on the guest list.

Many are related. Constantine's eldest son, Pavlos, exchanged a bear hug with Spain's Felipe, his first cousin, on the steps of the cathedral moments before the ceremony started.

Thousands of people had earlier queued for hours outside an adjacent chapel, where Constantine's coffin draped in a Greek flag was placed, to pay their last respects.

"I was and will remain a royalist," said Dionysios Klonaris, 76. "I'm sad and proud that I was able to honour him until the final seconds of his life".

His friend, Aphrodite Koulouris, 70, added: "I live for the moment that his heir, Pavlos, becomes king."

Constantine was 27 years old and had been king for three years when he was forced into exile in 1967 with his wife Princess Anne-Marie, the youngest daughter of King Frederick IX of Denmark, and his family.

He was deeply unpopular for his decision to swear-in the military junta who seized power in April that year. He briefly cooperated with them before staging a failed counter-coup that led to his exile.

The junta abolished the monarchy in 1973; in a referendum after it fell in 1974, Greece rejected monarchy again.

Monday's service, officiated by the country's Archbishop, Ieronymos, was private, reflecting Constantine's status as a former king. Some onlookers booed the culture minister, reflecting anger that the funeral was not more official.

In the 1990s, Constantine was stripped of his Greek citizenship and the state seized a family estate at Tatoi and a palace on the island of Corfu where Britain's Prince Philip was born.

Constantine will be buried in Tatoi, where his ancestors are also laid to rest.

Additional reporting by Renee Maltezou, Angeliki Koutantou, Michele Kambas, Stamos Prousalis; Editing by Toby Chopra and Philippa Fletcher

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