Alber Elbaz, a Moroccan-born Israeli fashion designer who rejuvenated Lanvin and had recently launched his own venture, AZ Factory, died on Saturday in Paris. He was 59.

Richemont, the company backing Mr. Elbaz’s project, confirmed the death on Sunday. A spokeswoman for Richemont said the cause was Covid-19.

“Alber had a richly deserved reputation as one of the industry’s brightest and most beloved figures,” Richemont’s chairman, Johann Rupert, said in a statement. “I was always taken by his intelligence, sensitivity, generosity and unbridled creativity.”

“You made us dream, you made us think, and now you fly,” AZ Factory wrote on its website. “Love, trust and respect, always. ❤️ Alber, We Love you Forever.”

Mr. Elbaz had just launched AZ Factory after a five-year hiatus following his abrupt firing from Lanvin, where he was fashion director from 2001 to 2015. During 14 years there, he turned Lanvin, the oldest surviving but dusty French fashion house, into a more modern and prominent brand whose creations were worn by the likes of Beyoncé, Meryl Streep, Lupita Nyong’o, Pharell Williams, Natalie Portman and Harry Styles.

A beloved designer, Mr. Elbaz repeatedly said that for the elegance and extravagance he brought to his creations, he tried to remain simple in private. He once compared the job of a designer to a concierge’s in a fancy Manhattan hotel.

“You have to go back to nothing in order to maintain the dream,” Mr. Elbaz told The New Yorker in 2009.

Starting his new brand, he said, was like giving birth.

“My hormones are burning,” Mr. Elbaz told The New York Times in January. “I’m so itchy. I cry and laugh within seconds.”

Elizabeth Paton contributed reporting.