Liliane’s husband, André Bettencourt, looked on passively while his wife lavished a fortune on Banier. A politician, he acquiesced in the relationship while he pursued his own professional and personal interests. His daughter was less indulgent. In December 2007, shortly after André’s death, a domestic servant claimed to have overheard Banier and Liliane discussing a plan to adopt him as her son and legal heir. “That was too much,” Françoise recalled. “This man had denigrated my father, manipulated my mother, and shattered our family.” It was at that point that she filed a criminal complaint against Banier.

Against the backdrop of a lengthy investigation, the Bettencourt Affair became daily fodder for French press stories calling Banier a “gigolo,” questioning both Liliane’s sanity and her daughter’s motives. The media also dredged up the darker chapters of the family’s history: Liliane’s father, Eugène Schueller, founder of L’Oréal, had been investigated as a Nazi collaborator after the war and her husband, André, had written anti-Semitic diatribes for the pro-German press. It was a public-relations disaster for L’Oréal and the Bettencourt family. There was even speculation that L’Oréal’s Swiss partner, Nestlé, might take advantage of the suit to swallow up the French company.

A major turning point came in June 2010, when the press reported that Liliane’s butler, Pascal Bonnefoy, had secretly recorded roughly 28 hours of the heiress’s conversations with her financial advisers and lawyers. Among other things, leaked transcripts revealed tax evasion schemes, secret Swiss bank accounts, illegal political contributions, conflicts of interest, and possible interference in the case by President Sarkozy.

Underlying it all was Liliane’s evident confusion, which allowed her advisers to do what they wanted with her money. If there was an abuse of weakness, it was apparent that Banier was not the only abuser. By the time the case finally went to trial in January 2015, Banier was joined by nine other defendants, including a former labor minister, accused of illegally receiving Bettencourt money on behalf of Sarkozy‘s presidential campaign. Sarkozy himself was investigated at one point, but the case against him was finally dropped for lack of evidence.

The 2015 trial hinged on the question of Liliane Bettencourt’s mental health. No one could contest her right to give Banier whatever she wanted as long as she was lucid. But a panel of medical experts traced her mental incapacity back to her September 2006 hospitalization following a fall. Whatever she gave Banier after that date was subject to question legally and ethically. During the trial, Banier adamantly denied that Liliane’s faculties were diminished: “Do you think the people at L’Oréal kept a nutcase around since 2003?” Prosecutor Gérard Aldigé was unmoved. In a fiery final statement, he charged that Banier had “imposed his control over [Liliane] like a spider spinning its web. And once he had her in his net, he never let her go. She became his thing. He dealt with her like a vampire.”

Banier and Bettencourt during happier times while attending the Trophy 1992 Ceremony; Banier photographed on the 19th day of his trial where he is accused of taking advantage of Liliane Bettencourt. Left, by Eric Robert/Sygma/Getty Images; Right, by Caroline Blumberg/EPA/REX/Shutterstock.

The decision that came down on May 18, 2015 was harsh: Banier was convicted of abuse of weakness, sentenced to two and a half years of hard prison time, and ordered to pay €158 million in damages to Liliane Bettencourt. Seven other defendants, including Liliane’s financial advisor, lawyer, and notary, were also convicted and given lesser sentences. Claiming not to have the money, Banier appealed. It proved to be a smart move; the second trial, in May 2016, handed him a much better verdict. The conviction was upheld, but his prison sentence was suspended and the damages were canceled. Banier was thus free to enjoy his lavish lifestyle with the remainder of Liliane’s largesse.