George Michael, the pop artist and founding member of the duo Wham!, has died at the age of 53. The singer sold more than 100 million albums over a career spanning almost four decades.

Michael died at his home in Goring-on-Thames, England, on Christmas Day. His manager, Michael Lippman, said the cause of death was heart failure.

In a statement, Michael’s family commented, “It is with great sadness that we can confirm our beloved son, brother and friend George passed away peacefully at home over the Christmas period.”

The London-born singer, whose real name was Georgios Kyriacos Panayiotou, formed Wham! in 1981 with schoolfriend Andrew Ridgeley, and the pop duo went on to have a string of hits, including “Wake Me Up Before You Go-Go,” “Club Tropicana” and “Last Christmas.”

Michael and Ridgeley parted ways in 1986, and the former embarked on a solo career. His first album, “Faith,” sold more than 25 million copies, and won a Grammy. The follow-up, “Listen Without Prejudice Vol. 1,” resulted in a legal dispute with U.S. record label Sony after Michael became frustrated with how they had handled the release. Plans for “Listen Without Prejudice Vol. 2” were shelved, and his next album, “Older,” achieved limited success. Two records followed: “Songs from the Last Century” and “Patience.”

Michael suffered from bouts of depression and drug problems, as well as the occasional brush with the law. He spent four weeks in prison in 2010 following a drug-driving conviction.

Michael almost died from pneumonia in 2011 when he was on tour in Vienna. He was hospitalized, and later said it had been “touch and go” whether he lived.

According to his Facebook page, Michael had recently been putting the finishing touches to a documentary film “Freedom,” which was set to air in March.

Michael had kept a lower profile in recent years but he remained a highly identifiable figure in pop culture. Michael made two guest star appearances as himself in the 2008-2009 ABC drama “Eli Stone.” The titular lawyer character was a devotee of Michael’s music, and his song “I Want Your Sex” figured into the plot of an episode involving a student who gets expelled for playing the song during a school assembly. Many of the show’s episodes were named after Michael songs.

“Eli Stone” co-creators Greg Berlanti and Marc Guggenheim expressed grief over his passing and praised his artistry.

Among the other notables who were quick to praise Michael’s legacy as an artist and as a person was James Corden, host of CBS’s “The Late Late Show with James Corden.” Michael was in part the inspiration for Corden’s enormously popular “Carpool Karaoke” segment, featuring Corden driving around Los Angeles in a small car with a superstar belting out their hits. Corden first did the bit with Michael on a British TV special in 2011. It was such a hit that Corden decided to revive it after he moved to the U.S. to take over “Late Show” in 2015.

Tributes have been pouring onto social media, including from Corden and Elton John: