COPENHAGEN, Oct 5 — The queen of Denmark’s decision to strip four of her grandchildren of their titles has sparked unprecedented royal drama in Copenhagen and led her enraged son to air the family’s dirty laundry in public.

Queen Margrethe II announced last week that the four children of her youngest son, 53-year-old Prince Joachim, would no longer be able to use the title of prince and princess after January 1.

She apologised on Monday for the hurt caused.

But Margrethe stood by the decision, which was intended to allow Nikolai, 23, Felix, 20 — born from Joachim’s first marriage — Henrik, 13, and Athena, 10, to live normal lives without royal obligations.

The move followed a trend among other European royal families to slim down their monarchies, including in Britain where the Windsors face their own family feud.

"Holding a royal title involves a number of commitments and duties that, in the future, will lie with fewer members of the royal family,” Europe’s only reigning queen said in a statement.

But Prince Joachim saw it as a snub and was quick to speak out in the media.

"On May 5, I was presented with a plan. That this whole issue of my children’s identity would be removed when they each turned 25. Athena will turn 11 in January”, he told Danish tabloid B.T.

"Then, I received five days’ notice” that the decision had been accelerated.

His first wife Alexandra also told B.T. she and her children were "shocked”, while her eldest son expressed his sadness.

"I’m very bewildered as to why this had to happen like this”, Nicolai told tabloid Ekstra Bladet.

The outpourings sparked surprise in the Scandinavian country, coming just days after the hugely popular royal family had celebrated the queen’s 50th anniversary on the throne with pomp and smiles.

There is "no tradition in Denmark of members of the royal family discussing with each other in public”, historian Lars Hovbakke Sorensen told AFP.

Prince Joachim said he had "unfortunately” had no contact with his mother or elder brother Crown Prince Frederik since the queen’s announcement.

"It’s also family. Or whatever one could call it”, he told B.T.

In another swipe, his French-born wife Princess Marie said the couple’s relationship with Crown Prince Frederik and his Australian-born wife Mary was "complicated”.

The media then dug up another old family spat, namely Joachim and Marie’s claims that their 2019 move to Paris — where Joachim is the Danish embassy defence attache — was not of their "own choice”.

Yet the queen’s decision did not surprise royal watchers.

It’s "natural, reasonable and necessary”, said historian Sebastian Olden-Jorgensen.

The queen’s four other grandchildren born to Crown Prince Frederik, 54, will retain their titles.

Back in 2016, the queen decided however that when they come of age only the future king, Prince Christian, will receive an appanage.

Stripping Joachim’s children’s titles is just another move in the same direction, experts said.

"She has wisely chosen to do this herself and not to leave it to her successor, the Crown Prince”, Olden-Jorgensen said.

"It is much easier for her to do to this to her son than for him to do it later to his brother,” he added.

Nonetheless, the heated reactions by Joachim’s family "indicate there is a conflict and a total breakdown in communication,” columnist Jacob Heinel Jensen wrote in B.T.

The queen’s apology on Monday came in a statement.

"I have underestimated the extent to which my younger son and his family feel affected... and for that I am sorry,” she said.

"I now hope that we as a family can find the peace to find our way through this situation.”

An opinion poll conducted by Voxmeter suggested 50.6 per cent of Danes support her decision while 23.3 per cent disagree.

This is not the royal family’s first scandal, though rarely have they been so sensational.

In 2002, the late Prince Consort Henrik made headlines when he fled to his chateau in southern France to "reflect on life”, complaining he didn’t receive enough respect in Denmark, after Crown Prince Frederik was chosen to represent the queen at a New Year’s ceremony instead of him.

And just months before his 2018 death, Henrik, who suffered from dementia, announced he did not want to be buried next to his wife because he was never made her equal. — AFP