David Letterman vs. Jay Leno: A Timeline of Their Legendary Late-Night Rivalry

Looking back at a decades-long history of bad blood

David Letterman, host of CBS’s “Late Show,” announced that he will retire in 2015 during Thursday’s taping of the show, which he has hosted for more than 20 years.

Interestingly, the announcement comes shortly after his late-night competitor, former “Tonight Show” host Jay Leno, stepped down from the NBC series. Given the bitter history between Leno and Letterman, one has to wonder whether Letterman was just holding out so that he could outlast Leno.

See video: Watch David Letterman Announce His ‘Late Show’ Retirement

With Letterman preparing to ride off into the sunset, TheWrap looks back at the decades-long beef he harbored with Leno.

1991: “Tonight Show” host Johnny Carson announces his retirement, fueling speculation that Letterman — in some people’s eyes, Carson’s heir apparent — would step into his shoes. Instead, Leno got the job.

See video: David Letterman Retiring: 11 Most Memorable Career Moments

Later, with Letterman appearing as a guest on “Tonight,” Carson asked him, “Just how p—ed off are you?” Letterman replied, joking, “You keep using language like that, you’re going to find yourself out of a job.”

1992: Letterman — who’d had a show, “Late Night With David Letterman,” on NBC — bails for CBS to launch “Late Show,” putting him in direct competition with Leno.

2010: Letterman and Leno set aside their differences long enough to film a Super Bowl commercial — during which Letterman gets a dig in at Leno by imitating him.

2013: Letterman gets in another shot at Leno in the form of a backhanded compliment, telling Oprah Winfrey that Leno is “the funniest guy I’ve ever known” — but also “maybe the most insecure person I have ever known.”

2013: After Leno announced his retirement from “Tonight.” Letterman once again took a shot-with-a-side-of-nice at Leno, saying that his rival was “going out on top” — then poking fun at the disastrous attempt a few years earlier to replace Leno with Conan O’Brien.

“It seems like we just went through this. Didn’t we just go through this? Jay Leno now is being replaced, and this is the second time this has happened,” Letterman joked. “I mean, it’s crazy. He’s being replaced by a younger late-night talk show host–what could possibly go wrong?”