During this period, Boyer had continued making European films, and with
Mayerling in 1936 it made him an international star. The offscreen Boyer was bookish and private, far removed from the Hollywood high life. But onscreen he made women swoon as he romanced
Marlene Dietrich in
The Garden of Allah (1936),
Greta Garbo in
Conquest (1937), and
Irene Dunne in
Love Affair (1939). He became a major star in
The Garden of Allah, which was his first film in
Technicolor.
In 1938, he landed his famous role, as Pepe le Moko, the thief on the run, in
Algiers an English-language remake of the hit French film
Pepe le Moko with
Jean Gabin. Although he never invited costar
Hedy Lamarr to "Come with me to the Casbah", the line would stick with him, thanks to generations of impressionists. Boyer's role as Pepe Le Moko was already world famous when animator
Chuck Jones based the character of
Pepe le Pew, the romantic skunk introduced in 1945's
Odor-able Kitty, on Boyer and his most well-known performance.
He played in three classics of unrequited love with some of greatest leading ladies :
All This and Heaven Too (1940), opposite
Bette Davis,
Hold Back the Dawn (1941), opposite
Olivia de Havilland, and
Back Street (1941), opposite
Margaret Sullavan. Charles was made a naturalized citizen of the United States in 1942.
In contrast to his glamorous image, Boyer began losing his hair early, had a pronounced
paunch, and was noticeably shorter than leading ladies like
Ingrid Bergman. When
Bette Davis first saw him on the set of
All This and Heaven Too, she did not recognize him and tried to have him removed from the set.
In 1943, he was awarded a Honorary Oscar Certificate for "progressive cultural achievement" in establishing the French Research Foundation in
Los Angeles as a source of reference (certificate). He never won an
Oscar for acting, though he was nominated four times - for
Conquest (1937),
Algiers (1938),
Gaslight (1944) and
Fanny (1961).
Charles Boyer is best known for his role in the 1944 film
Gaslight in which he tried to convince
Ingrid Bergman's character that she was going insane. He became famous for his declarations of love in movies with Dietrich, Garbo or Bergman. And in the 1940s he was the voice of Capt. Daniel Gregg in
Lux Radio Theater's presentation of
The Ghost and Mrs. Muir.