“Je t’aime… moi non plus”

Jane Birkin, who helped define chic female sexuality of the 1970s as an actress in arty and erotic European movies and in her relationship — equal parts romantic and artistic — with the singer Serge Gainsbourg, died on Sunday in Paris. Ms. Birkin, who later became known for inspiring one of the best known lines of luxury handbags, was 76.

Her death was confirmed by President Emmanuel Macron of France, who called her “a French icon” in a   message on Twitter . The   French news media   reported that Ms. Birkin had been found dead at her home but that the cause was not immediately known.

The child of a famously beautiful actress and a socially connected British naval officer, Ms. Birkin led a life guided by many happy accidents.

While she was on a flight in 1984, a plastic bag in which she was keeping her possessions broke, leading her to complain aloud that Hermès did not make a bag that could fit all her things. The man sitting next to her happened to be   Jean-Louis Dumas , then the head designer of Hermès (and later its chief executive). The company released the Birkin bag line the same year — in just the large size she had requested.

Standard Birkin bags   now sell   for $10,000, and the difficulties of obtaining one — given a complex manufacturing process and a deliberately rationed supply to boutiques — have given the bag the cachet of exclusivity.

Her relationship with Mr. Gainsbourg began just as fortuitously, in 1968. She was in her early 20s, her first marriage having fallen apart, when, without particular renown as an actress and without speaking a word of French, she managed to be cast in a French movie, “Slogan,” starring Mr. Gainsbourg.

The two fell in love, but Ms. Birkin did not see a way to remain long in France. Then, dining out one night, she had a chance encounter with the French director   Jacques Deray , got hired to act in a movie of his, stayed in the country and solidified her relationship with Mr. Gainsbourg.

She lived in France for the rest of her life, and her engagement with Mr. Gainsbourg and his music proved equally enduring.

The most notable product of their collaboration and romance was their 1969 hit recording of Mr. Gainsbourg’s song   “Je t’aime… moi non plus”   (“I Love You… Me Neither”).

In the song, a duet, Mr. Gainsbourg speaks of sex in a low, conversational voice as Ms. Birkin confesses her love in suggestive murmurs and moans and the high-pitched singing of an ingénue.

The song was condemned by the Vatican and banned in several countries and by the B.B.C. television network. But it sold millions of copies.

Nearly 50 years later, in 2018, Ms. Birkin was still singing music by Mr. Gainsbourg, by then on a world tour of orchestral versions of his songs.

“If I am singing in Argentina in two weeks’ time,” she   told   The Guardian, “it is because of ‘Je t’aime.’”

Jane Mallory Birkin was born in London on Dec. 14, 1946, to Judy Campbell, an actress who gained renown for performing for British troops with Noël Coward during World War II, and Cmdr. David Birkin of the Royal Navy.

In 2021, her father’s exploits during World War II were   recounted   in “A Dangerous Enterprise,” a book by Tim Spicer, a former British military officer. Commander Birkin’s duties included navigating boats on moonless nights across the English Channel to bring to safety Allied spies, stranded airmen and escaped prisoners of war who had found themselves in France.

Ms. Birkin, at 18, married the British composer John Barry, known for arranging the trademark theme to James Bond movies, and they had a daughter, Kate. At 20, Ms. Birkin appeared in Michelangelo Antonioni’s hit 1966 movie, “Blow Up,” an erotic tale of a London fashion photographer. She played a fashion model — the credits listed her as only The Blonde — and gained some attention for a risqué nude scene.