The Wildenstein family entered the art world in the 1870s in Paris when Nathan Wildenstein, Guy’s great-grandfather, helped a client sell some paintings while he was working as a tailor. Nathan opened his own gallery the same decade. His firm, Wildenstein & Co., has been family-run since then.

Five generations later, the art-dealing tradition continues through Guy, in charge of the Wildenstein Institute, whose ‘catalogues raisonnes’ for the most important artists of the 19th and 20th centuries are so exhaustive that a work by Monet would be worthless without a so-called Wildenstein index number.

The family’s days of hoarding acquisitions may be over. While sales have proceeded, the family’s disinterest in contemporary art means no new works have been purchased for the trust since its creation.

“The contemporary art market isn’t my craft,” Guy Wildenstein said, adding that buying very expensive works “that might be worthless tomorrow” didn’t make sense to him. “I stuck to what I knew well.”

Fiscal Risks

Guy said he didn’t know there was any fiscal risk when he didn’t declare the trusts in his inheritance-tax bill, and none of his advisers and lawyers told him of any, according to the court indictment.

The assets held in trusts weren’t legally Daniel’s, his lawyers have said. Instead, they belonged to the trusts and therefore shouldn’t count for estate taxes. French prosecutors argue that the trusts aren’t truly independent, pointing to evidence that the Delta Trust became a source of bounty for Guy and his brother Alec, who died in 2008.

Unaware of the trusts when it settled in 2002, France accepted a set of bas-reliefs by Marie Antoinette’s favorite sculptor to cover an estate tax bill it believed worth no more than 17.7 million euros. It was alerted to the trust several years later as Daniel’s second wife, Sylvia, fought for her share.

Daniel’s Death

In October 2001, Daniel, who had battled cancer, fell into a coma and died. Two weeks later, Sylvia signed away her rights to her late husband’s estate. According to Sylvia, her stepsons -- Guy and Alec -- told her the taxes would bankrupt her if she didn’t. Several years later, she sued Guy and Alec claiming she was cheated out of her inheritance and that the family was sitting on trusts and real estate worth billions.