NEW YORK, NY.- Daniel Brühl had just started shooting the series “Becoming Karl Lagerfeld” in Paris last year, and he could feel the French crew’s eyes on him. The German actor, who was playing the title role, was all nerves. After his first few days on set, he returned to his dressing room to find an enormous bouquet of, as he put it, “the biggest and reddest roses I’ve seen in my life.” There wasn’t any note.

When Brühl put the flowers in a vase at home later, however, he spotted a small card tucked among them. “It said ‘For Karlito, from Jacquot,’” he recalled in a video interview. “Nothing else.”

He realized the gift was from his co-star Théodore Pellerin, a Canadian actor who portrays Lagerfeld’s great love, Jacques de Bascher; Pellerin had signed the card with their characters’ nicknames. Brühl knew then that he and the series, which revolves around the intense love story between the two men, would be fine.

“Becoming Karl Lagerfeld,” which premiered Friday on Hulu, is set mostly in the 1970s, a decade that was key to Lagerfeld’s development as a fashion designer as well as his personal evolution. It was before he formed his distinctive look of a sharp-angled figure decked out in monochromatic costumes, high collars, black gloves — although the tinted glasses and signature ponytail make their appearance. Like Andy Warhol, another secretive pop-culture icon, Lagerfeld meticulously manufactured his public identity, Brühl said: “So, who was the person before he was famous?”

Brühl briefly met Lagerfeld, who died in 2019, about 20 years ago on a photo shoot and remembers him as “very charming.” When Brühl had to become the designer, he did a deep dive, reading up, for example, on the many artistic fields Lagerfeld had been interested in: “literature, arts, architecture, design and fashion, of course,” Brühl said. “I wasn’t bored a single second spending time with Karl Lagerfeld.”

Still, there needed to be a way in, and for creator and showrunner Isaure Pisani-Ferry, it was de Bascher, who was 21 to the designer’s 38 when they met. “It was this moment in the ’70s when he falls in love, which means loss of control — and this is a man who needs to be in control,” Pisani-Ferry said of Lagerfeld in a video conversation.

De Bascher was the opposite, a dandy who enjoyed dissolute idleness with an elegant insouciance. His indolence and penchant for excess both fascinated and troubled Lagerfeld, a workaholic who did not drink or do drugs, and did not seem interested in sex, either. Lagerfeld later said they never consummated their relationship, and an idiosyncratic seduction sequence is among the most poignant scenes in the series.

Lagerfeld’s self-possession translated to a perpetually composed demeanor. In the show, rare glimpses of his inner turmoil come when he devours a lemon tart or a chocolate bar with a pleasureless intensity. “Why is this person so guarded?” Brühl wondered. “What is he afraid of? Fear, as we know, is always such an interesting motive. But it was fear on the one hand and extreme courage on the other hand, because he made his way as a gay young German in the ’70s, when being German in Paris was not precisely the most attractive thing.”

This was a stark contrast to de Bascher, who came from a noble provincial family and inserted himself into the Parisian elite with ease. Frustrated by Lagerfeld’s restraint, the young dilettante simply looked elsewhere for his fun, most notoriously with Lagerfeld’s longtime frenemy Yves Saint Laurent (Arnaud Valois), who became obsessed with him.

Although Saint Laurent has very little screen time in the series, he has an outsize impact. He constantly haunts Lagerfeld, who was acutely aware of his own artistic shortcomings in comparison with his brilliant, groundbreaking rival.

“Lagerfeld was superior to those who surrounded him then, a lot more cultured and refined, and likely smarter and more of a strategist, but it was painful to him to see that he wasn’t a genius,” said Raphaëlle Bacqué, an investigative reporter for Le Monde. Bacqué’s biography, “Kaiser Karl,” inspired “Becoming Karl Lagerfeld,” and she is an executive producer of the show.

Lagerfeld’s complicated relationship with Saint Laurent was a major source of inspiration for Brühl, who has worked steadily in Europe and Hollywood since his breakthrough 20 years ago in the film “Goodbye Lenin!” (His next projects include Sam Mendes and Armando Iannucci’s upcoming HBO series, “The Franchise,” and the film “Eden” with Ron Howard.)

“What always interests me in life is envy and jealousy, and as an actor, this Mozart-Salieri dynamic with Saint Laurent was always a very strong, guiding motif,” Brühl said. “It explains a lot of his love, hatred, frustration, motivation and the fire that he had in himself to become someone. But there was a complex that never quite disappeared because he knew that, ultimately, Saint Laurent will always be regarded as the god and as the artist.”

When de Bascher began sleeping with Saint Laurent, it made things even more complicated for Lagerfeld, Pisani-Ferry said: “You have the feelings and the professional, the need for recognition and the question of sexuality all mixed up in this one phase of his life.”

Lagerfeld supported de Bascher financially and introduced him to his circles. But he also benefited professionally from the relationship. De Bascher was a source of inspiration for Lagerfeld, providing a connection to Paris’ ebullient, creatively fertile nightlife. As Jérôme Salle, an executive producer who also directed three of the show’s six episodes, points out, Paris was a heady place in the 1970s.

“It was supercreative, supercrazy,” he said. “It was this magical moment between the sexual revolution and AIDS.”

De Bascher made the most of that window, and the show spends plenty of time with this proto-influencer who made money from his leisure as best he could.

“He was influential through his style, his taste for the nightlife, the freedom with which he led his life,” Bacqué said. “Isaure is more lenient toward him, whereas I have mixed feelings: His laziness and his flippancy are exasperating, but at the same time, he’s attractive.”

All involved with “Becoming Karl Lagerfeld” agree that whatever the imbalance between Lagerfeld and de Bascher’s attitudes and abilities, their bond was real, even if it defied convention. Salle said that “for Jacques, the love is very sincere, and Karl loves Jacques as much as he can love someone.”

“What is very moving for me — and I spoke about that a lot with Daniel and Théodore — is that yes, this love story was toxic," he said. “But they did love each other.”

This article originally appeared in The New York Times.