Jon Jones has confirmed his retirement and Britain's Tom Aspinall has now been installed as the UFC's heavyweight champion.
The 37-year-old Jones has been the UFC's light-heavyweight and heavyweight champion, most recently fighting in November when he beat Stipe Miocic.
He became the youngest ever UFC champion in 2011, defeating Mauricio Rua at 23 years of age. However, his career has been marred by scandal following positive tests for performance-enhancing substances and illegal non-performance-based substances. Jones has also had issues with US law enforcement during his time with the UFC.
"Today, I'm officially announcing my retirement from the UFC. This decision comes after a lot of reflection and I want to take a moment to express my deepest gratitude for the journey I've experienced over the years," Jones stated.
"From the first time I stepped into the Octagon, my goal was to push the boundaries of what was possible in this sport. Becoming the youngest UFC champion in history, defending my title against some of the best fighters in the world and sharing unforgettable moments with fans across the globe - these are memories I'll cherish forever.
"I've faced incredible highs and some tough lows, but every challenge has taught me something valuable and made me stronger, both as a fighter and as a person."
Britain's Tom Aspinall, 32, who was the interim heavyweight champion, now gets elevated to full champion following three consecutive wins over Marcin Tybura, Sergei Pavlovich and Curtis Blaydes.