'French Elvis' Johnny Hallyday Dies at 74

French singer, actor, and rock star Johnny Hallyday passed away today at the age of 74. Agence France Presse reports that the performer has been battling lung cancer for some time now.

Hallyday, whose real name is Jean-Phillippe Smet, popularized rock and roll in the French speaking world. He began by covering existing hits by artists like Gene Vincent, Eddie Cochrane, and Elvis -- earning him the nickname "French Elvis." He was also widely known as "the biggest rock star you've never heard of," since Hallyday was so popular and successful in the French-speaking world yet little known in English-speaking communities.

Hallyday sold over 110 million records worldwide. He's one of the most successful recording artists of all time. Eighteen of his albums went platinum, and he completed a total of 181 tours.

Hallyday had a fifteen year marriage to a French singer named Sylvie Vartan. The two were revered as a power couple in the French entertainment world. They had a son together in 1966, David Hallyday, who continues to have a successful career in his own right as a French-language singer-songwriter.

Hallyday touched the lives of so many, and influenced those outside the U.S. or other English-dominant countries. He was an icon for performers who wanted to do it their own way. One performer he was closely associated with was Celine Dion, who took to Twitter shortly after his death to mourn the rock legend.

I'm very sad to hear the news that Johnny Hallyday passed away. He was a giant in show business...a true icon! My thoughts go out to his family, his loved ones, and to the millions of fans who adored him for many decades.He will be sadly missed, but never forgotten.- Céline xx…

— Celine Dion (@celinedion) December 6, 2017