When the lifeless body of Christina Onassis was found on November 19, 1988, near Buenos Aires, not only did speculation over the cause of her death begin, but a legend was born. At the center of attention was her fourth husband and the father of her only daughter Athina — Thierry Roussel. Surrounded by an aura of scandal and doomed love, his figure still raises many questions. Although Roussel turned 72 in February 2025 and is best known for his relationship with the daughter of Greek magnate Aristotle Onassis, his personal biography is far more complex and intriguing than it may seem at first glance. Beneath the image of a frivolous playboy lay an aristocratic lineage and a substantial family fortune.
Thierry Patrick François Roussel was born on February 16, 1953, in Neuilly-sur-Seine, an upscale suburb of Paris. His father, Henri Julien Gaston Roussel, served as president and CEO of the pharmaceutical company Roussel Uclaf. His mother, Francine Grinda, was the daughter and granddaughter of prominent French politicians. After graduating from high school in 1972, Thierry enrolled in the economics faculty at the prestigious Pantheon-Assas University in Paris’s Latin Quarter. His family’s connections were extensive: one of his sisters held the title of duchess, and his maternal uncle was a well-known tennis player who represented France in the Davis Cup. The family’s fortune was founded back in the 1920s, when their pharmaceutical corporation became the second largest in France. Later, in 1997, it was sold to the German conglomerate Hoechst AG, and in 2004 it became part of the Sanofi Aventis group.
Thierry Roussel’s rise to media fame was tied to his tumultuous romance and subsequent marriage to Christina Onassis in 1984. Their union, surrounded by numerous rumors, proved short-lived. By the time their daughter Athena was born on January 29, 1985, the couple was already in the process of divorcing. The reason was the French businessman’s multiple infidelities. It became clear that Roussel was leading a double life, maintaining a relationship with Swedish model Marianne “Gaby” Landhage. Furthermore, his first son with Gaby, Erik, was born in July 1985, just a few months after Athena. Their second child, a daughter named Sandrine, was born in May 1987. Ultimately, in 1990, Thierry married his longtime love, and young Athena, who was under her father’s care, served as one of the bridesmaids at their wedding. Later, the couple had another daughter, Johanna.
A month after his former wife’s death, Roussel told an Argentine publication that he was the only person who truly loved her. He claimed he had offered her everything—love, family, and a peaceful life—but could not overcome her inner turmoil, which proved stronger than their feelings. However, his subsequent actions suggested otherwise. During Athena’s childhood, Christina’s inheritance was managed by a board of trustees, which included Roussel himself. He was constantly at odds with the Greek administrators, threatening to move his daughter to Paris, which would have resulted in higher capital taxes. In 1999, amid this struggle, a Vaduz court ruled to transfer the management of the estate to a Swiss consulting firm. When Athena reached adulthood, she gained control of half of her fortune. However, at 21, she was denied the right to head the Onassis Foundation, established by her grandfather. The board of directors considered her unfit to continue the family legacy, as she had no connection to Greece—a heritage from which her own father had largely distanced her.
