Brandon Blackstock, a talent manager known as both the ex-husband of Kelly Clarkson and the former stepson of Reba McEntire, has died. He was 48.

“It is with great sadness that we share the news that Brandon Blackstock has passed away,” a rep for the family tells PEOPLE in a statement. “Brandon bravely battled cancer for more than three years. He passed away peacefully and was surrounded by family. We thank you for your thoughts and prayers and ask everyone to respect the family’s privacy during this very difficult time.”

On Wednesday, Aug. 6, Clarkson revealed Blackstock had been ill, and she postponed her Las Vegas residency to spend time with their children, River, 11, and Remington, 9.

“While I normally keep my personal life private, this past year, my children’s father has been ill and at this moment, I need to be fully present for them,” she wrote in a statement, apologizing to fans and expressing appreciation for their “grace, kindness and understanding.”

Blackstock also had two children from a previous marriage, Savannah and Seth, and became a grandfather in 2022 when his eldest child Savannah gave birth to a son, Lake.

In March 2024, Blackstock posed with River and Remington in photos at the Houston Rodeo, where the family enjoyed an outing with Blackstock’s brother Shelby and Shelby’s mother, Reba McEntire. McEntire was previously married to Blackstock’s father, Narvel Blackstock, from 1989 to 2015.

Narvel Blackstock previously served as Clarkson’s manager, and the singer and her future husband first met at a rehearsal for the Academy of Country Music Awards in May 2006, when Blackstock was still married to ex-wife Melissa Ashworth.

“This guy walks by, making everybody laugh. I said, ‘I’m gonna end up with him. I know it,’ ” Clarkson told PEOPLE in 2013.

Several years later, they reconnected at the Super Bowl, and Clarkson. They were married in October 2013, and her deeply personal 2015 song “Piece By Piece” was inspired by Blackstock and the stability she felt in their relationship, compared to the abandonment she felt from her father as a child.

After their wedding, Blackstock — who was also Blake Shelton’s manager — became Clarkson’s manager, too.

“I wouldn’t have hired Brandon to be my manager if I didn’t see first-hand how great he is at that and how much he cares about Blake,” the star told Marie Claire in 2018. “And the way that [Blake’s] career has blown up, I would have hired Brandon regardless. He’s really talented at what he does and his mind really does work in a completely different way.”

Clarkson ultimately filed for divorce from Blackstock in 2020; they finalized the divorce in 2022.

“I think the thing about divorce — especially having it publicized, and people thinking they know the whole thing — the hardest part of that is, like, it wasn’t an overnight decision,” Clarkson later said of the split in 2023. “I wanted to make it beautiful. I wanted to make it awesome. I wanted to make it everything it possibly could be, and sometimes that just doesn’t happen.”

Blackstock is survived by his sons Seth and Remington, daughters Savannah and River, grandson Lake, father Narvel Blackstock and siblings Shelby, Shawna and Chassidy.