As soon as the news of his passing was announced, Cher took to social media to share her sorrow, writing:
“IVE TRIED… WORDS ARE IMPOSSIBLE GUI GUI FOREVER, CHOOCH”
She followed this up with a second message: “never forget....gui chooch”
The couple were married for four years in the 1970s and share a son, Elijah.
Other stars to pay tribute to the founding member of the Allman Brothers band include Ringo Starr, Peter Frampton, Melissa Etheridge and Keith Urban.
Gregg formed the band with his brother Duane, and they enjoyed great success in the early 1970s, before Duane was killed in a motorcycle crash.
Allman, the band’s lead singer and keyboardist, wrote several of their biggest hits, including ‘Whipping Post’, ‘It’s Not My Cross to Bear’ and ‘Midnight Rider’.
Many people who’ve never heard of the band will have heard their music - their song ‘Jessica’ was used as the opening theme tune to ‘Top Gear’.
The band’s bassist was tragically killed soon after Duane, and Gregg later went solo with the Gregg Allman Band. He was the recipient of several Grammy Awards and inducted into the Rock and Roll Hall of Fame, with many citing his work as “trail-blazing” and that of a rock pioneer.
Gregg was diagnosed with hepatitis C in 1999 and had a liver transplant in 2010.
It’s not the first time Cher has grieved for a former love. She paid emotional tribute to her ex-husband Sonny Bono, when he died in a skiing accident in 1998.