France's king of rock Johnny Hallyday dies at 74

French music icon Johnny Hallyday died Wednesday aged 74 after a battle with lung cancer, plunging the country into mourning for a national treasure whose rock 'n' roll entertained three generations.

The leather-clad would-be Elvis broke from France's classic "chanson" tradition in the late 1950s, selling more than 110 million albums and headlining 50 major tours.

"Johnny Hallyday has left us. I write these words without believing them. But yet, it's true. My man is no longer with us," his wife Laeticia Hallyday, 42, said in a statement issued overnight.

"He left us tonight as he lived his whole life, with courage and dignity."

Hallyday had announced in March that he had cancer and would undergo treatment.

President Emmanuel Macron was among the first to react to Hallyday's death, saying: "There is something of Johnny in all of us."

Former president Nicolas Sarkozy -- an adoring fan who once tried to tempt him back from tax exile in Switzerland -- said he represented "part of our personal history... our memories and emotions".

From early on in a career that would span over five decades, Hallyday drove his young fans wild, attracting 100,000 to a Paris square in 1963 and prompting scenes of hysteria until then unseen in a conservative France led by the stiff General Charles de Gaulle.

"He embodies the emergence of French youth culture and rock 'n' roll," said Serge Kaganski of the French music magazine Les Inrockuptibles.

Born on June 15 1943, Hallyday attempted suicide in 1966, collapsed on stage in 1986 and married five times -- twice to the same woman, the daughter of one of his oldest friends and songwriters.

Rumours of Hallyday's passing had flown online in recent weeks after he was admitted to hospital in Paris with breathing problems.

Hallyday, whose real name was Jean-Philippe Smet, spent six days under medical care before returning to rest at his home in Marnes-la-Coquette, west of the capital.

Fans had in the past week told French media they were so upset at the news of his deteriorating health they could not bare to listen to his songs.

"Until the very last moment, he held firm against this illness that had afflicted him for months, teaching us all extraordinary life lessons," his wife Laeticia said.

The rocker "lived his entire life wholly for his fans, who loved him and idolised him", she added.

- 'A true icon' -

News of Hallyday's death triggered tributes from Celine Dion and Lenny Kravitz.

"I'm very sad to hear the news that Johnny Hallyday passed away. He was a giant in show business... a true icon!" Dion wrote on Twitter.

"Your friendship, sweetness and support are imprinted in my heart. It is an honour to have known you and to have spent time with you and your beautiful family. Your soul is pure Rock and Roll," Kravitz tweeted.

"Repose en paix," he wrote in French, meaning "rest in peace."

French far-right leader Marine Le Pen expressed condolences on Twitter to Hallyday's family, describing him as "a singer who came from the people and who the people loved".

The French media was awash with tributes, with Le Figaro daily running the headline: "France's last idol is gone."

On Twitter, #JohnnyHallyday and #RIPJohnny were trending topics.

Yet throughout Hallyday's life, fame outside the French-speaking world had eluded him.

"My international career? It'll happen if it happens," Hallyday once told AFP. "But I don't specially want to succeed elsewhere. It's better to be king in one's own country than a prince elsewhere."