As MMA has evolved, UFC champions have become younger and younger.
The days when a 40-something Randy Couture could return from a 13-month hiatus to capture the heavyweight title are likely gone for good. Many hungry up-and-comers now fill every division and are knocking the majority of their elders down a peg well before they close in on 40 years old.
Obviously, there will be exceptions.
Anderson Silva hung onto his spot atop the middleweight division for years. While many would have begun to fade at his age, "The Spider" was only recently dethroned by Chris Weidman.
Here are the 10 oldest champions in UFC history.