After three generations of genteel discretion bordering on secrecy, the international banking family the Rothschilds has been riven by rival claims to a multibillion-euro fortune including a vast collection of art masterpieces.

The battle now playing out in the courts and media has pitched the 93-year-old senior baroness, Nadine de Rothschild – widow of Edmond de Rothschild, the late scion of the French-Swiss branch of the family – against her daughter-in-law, Ariane de Rothschild, the current baroness.

The lawsuits centre on the family’s extensive collection of furniture, priceless historic objects and paintings held at the baronial domain, the Chateau de Pregny in Switzerland, which one visitor described as a “mini Louvre”.

The Rothschild family maintains a code of silence over the exact contents of the chateau overlooking Lake Geneva – where photographers and nosy visitors are banned – but they reportedly include treasures including Louis XVI furniture and works by Goya, Rembrandt, Fragonard, El Greco and Boucher.

Nadine claims that her husband, who died in 1997, bequeathed her a substantial part of this collection, which she wants to put in a new museum in Geneva, dedicated to displaying the collection of the Edmond and Nadine de Rothschild Foundation she has created.

Ariane – who was married to Edmond and Nadine’s only child, Benjamin, who died in 2021 – insists the collection must remain intact and in the chateau.

In court documents, Ariane, 60, has accused the elder baroness of being influenced by her advisers, drawing a parallel with the late L’Oréal heiress Liliane Bettencourt. In 2011, Bettencourt’s daughter sought to have her declared of unsound mind after she lavished an estimated €1bn in gifts on a young photographer friend.

Speaking from her home in the Swiss countryside, Nadine, who used to appear regularly on television chatshows talking about manners and etiquette, told the Guardian: “I knew Liliane and I can tell you she was absolutely not a woman you could make do anything she didn’t want. And neither am I under anyone’s influence. You can tell from my voice and answers that it would be hard to influence me.

“I am the last Rothschild baroness of my generation. All the others have died. To end my life with a major legal battle like this of course upsets me.

“In the beginning I opened my arms to my daughter-in-law; there are photos of us together, I was generous in my personal gifts to her.”

The senior baroness has known harder times. Born Nadine Lhopitalier, she grew up in a communist-supporting family and left home at 14. Two years later, she was sewing poppers on Peugeot sunroofs and working as an artists’ model. Later, she took the stage name Nadine Tallier and played in music halls and small film roles.

In the early 1960s, she met Edmond de Rothschild. She later recalled their first meeting, saying: “He looked at my ring and he said, ‘It’s lovely, but unfortunately the diamond is fake.’”

The couple married in 1963. From then on, all the jewels were real.

As the wife of the wealthiest member of the banking family, Nadine oversaw the running of their 14 properties, where, over several decades, they received the beau monde – including the Kennedys, Audrey Hepburn, Maria Callas, Princess Diana, Romy Schneider and Greta Garbo.

Nadine admits that she was an absent mother to Benjamin, who was brought up by nannies. He claimed she treated him as “an heir” and not a son. She insists she welcomed his wife, Ariane, into the family in 1999 and moved out of the 1,126sq metre Chateau de Pregny into a pavilion in the 18-hectare (44-acre) grounds, leaving the family home to the young couple, who had four daughters.

Nadine says that relations between the two baronesses became “irreparable” after Benjamin’s death. She has since left the estate and lives “comfortably” in the countryside outside Geneva.

Today, both sides have won legal battles, but the family war rages on. Ariane lost her attempt to ban Nadine from using Edmond’s name for her foundation; Nadine has lost any legal right to enter the château. A third lawsuit over ownership of the artworks and other items is dragging on.

A source close to the family said Ariane and her daughters would not discuss the falling out.

“Out of respect for all parties involved, the family is not commenting on this matter, which it is dealing with with the utmost restraint,” the source said in a statement. “The family is fully committed to its family activities, working daily to preserve and pass on its heritage.”

Nadine is less restrained.

“I inherited from my husband many objects that are in the Chateau de Pregny, but it has been impossible to recover them since my son’s death. That is why, sadly, I have been forced to take legal action.”

Representatives for Ariane have argued that Nadine made no claim on the works of art until after Benjamin’s death and this being the case, she no longer has a valid claim to them – a question at the heart of the current ongoing legal case.

“We are talking about major objects, classified historic objects that belong in a museum,” Nadine says. “I hardly see the younger generation [of Rothschilds] wanting to be burdened with such things, but in any case my granddaughters will inherit from me.

“I haven’t lost hope that my granddaughters will understand that this battle is between their mother and grandmother and not against them. My only hope is that one day they will appreciate that I am doing this for the honour of the family.”