Kelly Osbourne is mourning the loss of her father Ozzy following his death on Tuesday. Osbourne posted a brief message to her Instagram stories on Thursday afternoon. “I feel unhappy I am so sad,” she wrote. “I lost the best friend I ever had.”

Osbourne, fondly nicknamed the “Prince of Darkness,” was married to his second wife, television personality and music manager Sharon, from 1982 until his death. Together, they shared three children: Aimee, 41; Kelly, 40; and Jack, 39.

Ozzy Osbourne welcomed two children with his ex-wife Thelma Riley and three children with Sharon Osbourne. He also adopted Thelma's son from a previous relationship. Here's everything to know about Ozzy Osbourne's kids.

Ozzy Osbourne's daughter, Kelly Osbourne, got a whole perspective shift with her father's Parkinson's diagnosis.

They were just totally in love and devoted to each other, and that wasn’t for the cameras. That was just who they were.”

The musician’s death came just 17 days after he performed his final concert with Black Sabbath at England’s Villa Park, a swan song he’d been planning for months. “That show meant everything,” the source says. “It brought his career full circle.”

Tributes are pouring in from music legends and celebrities after Ozzy Osbourne, the rock and heavy metal icon turned reality show star, has died at the age of 76, according to his family.