Claude Ruiz-Picasso, who, after a legal fight that established him and his sister Paloma as legitimate heirs to their father, the great artist Pablo Picasso, managed his vast estate for more than 30 years, died on Thursday in Switzerland. He was 76.
His death was confirmed by his lawyer, Jean-Jacques Neuer, who did not give a cause or say where in Switzerland he died.
Claude and Paloma were the children of Picasso and Françoise Gilot, a French painter 40 years his junior, who, after a long and stormy relationship, left him in 1953. Picasso did not deny that he was Claude and Paloma’s father, but he was so angry when Ms. Gilot published a memoir, “Life With Picasso,” in 1964, that he cut off contact with her and their children. Ms. Gilot died in June.
In 1970, Claude Ruiz-Picasso and Paloma Picasso sued in a French court to be recognized as Picasso’s legitimate children. French law changed in 1972 to give children born out of wedlock rights of inheritance; the siblings won a court ruling in March 1974, almost a year after their father’s death, to further establish their legitimacy. The court said that Picasso had confirmed his paternity by dedicating paintings to them.
By then, Claude Ruiz-Picasso had been living in New York City since 1967. Over the next seven years, he studied at the Actors Studio; worked as an assistant to the fashion and portrait photographer Richard Avedon; and began a career as a photojournalist.
Mr. Picasso’s work eventually appeared in Vogue, Saturday Review, Time and Life magazines. He said that he had been inspired by the photojournalist David Douglas Duncan, who spent years creating a pictorial record of his father.
“Duncan was always around, clicking away, and I thought, oh, this would be an interesting occupation,” Mr. Ruiz-Picasso told the Picasso biographer John Richardson in a 2019 interview for Gagosian Quarterly, an art-world magazine published by the global gallery owner Larry Gagosian. “When I was about 17,” he added, “he very kindly gave me a professional camera.” It was a Nikon.
Claude Ruiz-Picasso was born on May 14, 1947, in Neuilly-sur-Seine, France. Paloma was born two years later. His half-siblings were Paulo, the son of Picasso’s marriage to the ballet dancer Olga Khokhlova, and Maya Ruiz-Picasso, whose mother was the model Marie-Thérèse Walter. Paulo Picasso died at 54 in 1975. Maya Ruiz-Picasso died last year at 87.
In 1989, after six years of squabbling among all Picasso’s heirs including his widow, Jacqueline Roque, over the distribution of the thousands of artworks he left behind and the communal right to exploit his name commercially, a French court appointed Mr. Picasso the estate’s administrator.
“I never expected or desired to have any kind of role like this, or have any influence over my father’s legacy,” he told Mr. Richardson. “So because of the Picasso Administration, little by little, I had to quit photography. Not all of a sudden but little by little.”
As the administrator, Mr. Picasso dealt with copyright and trademark issues, made licensing deals, battled with forgers and produced reproductions.
“I think he did an incredible job as a steward of his father’s legacy,” Mr. Gagosian, whose galleries have presented numerous Picasso shows, said in a phone interview. “He took it seriously and was extremely strict about how the Picasso image was handled.”
One of Mr. Picasso’s licensing deals involved selling his father’s name and signature in 1998 to PSA Peugeot-Citroen, the French automaker. Marina Picasso, Paulo’s daughter, challenged the deal in court. She told a French newspaper, “I can’t tolerate that the name of my grandfather and of my father be used to sell something as banal as a car.”
According to a 2016 Vanity Fair article about the Picasso art empire, Citroen paid a reported $20 million, plus royalties, for the deal, and had sold some 3.5 million Picasso cars at the time.
In July, Mr. Ruiz-Picasso was replaced as estate administrator by Paloma Picasso, a jewelry designer.
He is survived by his wife, Sylvie Vautier Picasso, and his sons, Solal and Jasmin.
In 2018, Mr. Ruiz-Picasso criticized the Musée Picasso in Paris for lending out too many of its Picasso works to the many exhibitions scheduled in France that year. He said that some of those works were fragile and shouldn’t be used to bulk up the shows.
“Many people expect to make discoveries that, at the end of the day, they do not make, and they are not satisfied with what is on offer,” he told The Times of London. “Among the exhibitions held, there is a load that are not necessary.”
In response, Laurent Le Bon, the chairman of the museum, said: “My objective is to ensure that the museum is not a tomb. Instead of the same old exhibitions on Picasso and women, Picasso and love, and Picasso and light, we are trying to develop new ideas.”