This Saturday, UFC 146 goes down in Las Vegas, Nevada, and the heavyweight title is on the line between current champion Junior dos Santos and former champion Frank Mir.
Also on the card is a fight between former heavyweight champion Cain Velasquez, and a participant in the Strikeforce Heavyweight Grand Prix, Antonio Silva.
Cain Velasquez was last seen at UFC on Fox 1, where he lost his title to dos Santos in the first round by knockout.
With the loss, Cain failed to defend his title, and joined a long list of champions who were never able to defend the belt.
Let’s take a look at some others.