"René Angélil passed away this morning at his home in Las Vegas after a long and courageous battle against cancer," his rep said in a statement on Thursday. "The family requests that their privacy be respected at the moment; more details will be provided at a later time."
Angélil died of throat cancer at his home in Henderson, Nevada, while under the care of a physician, the Clark County Office of the Coroner also confirmed in a statement on Thursday.
"We have determined Mr. Angélil's death was due to natural causes," John Fudenberg, Clark County coroner, said. "No further investigation into his death is expected."
Angélil has been in Dion's life since they met when she was 12 years old -- serving as both her manager and mentor -- even mortgaging his home to fund her first record, La voix du bon Dieu. The two's relationship turned romantic in 1987, and they were engaged in 1991. The couple tied the knot in December 1994, in a lavish ceremony at Notre-Dame Basilica in Montreal, Quebec.
Last month, the two celebrated their 21st wedding anniversary, with the 47-year-old singer Instagramming a sweet throwback photo of the two holding hands on their wedding day.
Angélil was first diagnosed with throat cancer in 1999. In 2014, Dion took an indefinite leave of absence from her Las Vegas residency to care for Angélil -- who underwent surgery to remove a cancerous tumor from his throat in December 2013 -- after his second cancer diagnosis.
"It's not hard to take time off," the legendary singer told ET in May
. "It's not hard to be with him, obviously. It's not hard to be with the family and the kids. It's hard because life imposes things on you."
"We don't know what the future holds," Dion told ET in August
, adding that Rene told her to be "back, strong, [to] do it, still share your passion."
"He's been there for me all my life, and I've been there for him all my life," she continued. "There's a part of me that never really left the stage. I wanted to be there but I needed to be someplace else which was much more important at that time. To be by his side. To be by my family."
Angélil is survived by the couple's three children -- René-Charles, 14, and 5-year-old twins Nelson and Eddy. He also has three children from previous relationships -- Patrick, Jean-Pierre, and Anne-Marie.