05/18/2012 02:04 am ET Updated Dec 06, 2017

Conan O'Brien Visits Letterman, Both Mock Common Enemy Jay Leno (VIDEO)

To watch Conan's full, four-part interview on "The Late Show," visit the show's website.

Thursday night, Conan O'Brien appeared on "The Late Show with David Letterman," and the two late night hosts wasted no time addressing the denim elephant in the room: Jay Leno. In separate incidents over the last two decades, NBC favored Leno over each former "Late Night" host as the star of "The Tonight Show," and they spent a good portion of O'Brien's appearance on the CBS talk show swapping insights about their common ground.

"The longer we sit here, the more uncomfortable it'll make Jay," were the first words out of Dave's mouth after sharing an awkward yet knowing silent moment with Conan.

"You know Jay's watching right now," Conan joked. "He's getting a live feed in a satellite truck right now." Despite prodding from Letterman, Conan would not bring himself to say anything explicit to slam Leno throughout their interview, but did imply that the relationship between the two has been damaged permanently.

The majority of the first segment of O'Brien's interview was devoted to discussing the events that led to Conan's dismissal at "The Tonight Show," and Letterman's joy as he watched them go down. During the couple of weeks in January 2010 that negotiations at NBC were up in the air, many felt that Letterman's Leno-mocking play-by-play was the most entertaining he had been in years.

Calling the NBC about-face as the "Golden Age of Television," Letterman erupted in a fit of laughter as Conan told him he was glad someone got some enjoyment out of the period.

This marked the first time O'Brien has appeared on Letterman's show in 13 years, but the two men's careers have been inextricably linked. When Letterman jettisoned "Late Night" in 1993 after NBC named Letterman's pal Leno as Johnny Carson's "Tonight Show" successor instead of himself, the previously unknown O'Brien stepped in as the new host of the 12:30 show. Letterman's guest appearances on the struggling show indicated a public vote of confidence to the new program from Dave, and 16 years later, Conan reserved his final thanks on his last episode of "Late Night" for his television forebear Letterman.

In 2009, O'Brien was given "The Tonight Show," until NBC pulled the plug on the show after only seven months when O'Brien refused to push his show back half an hour to make room for the poorly-performing "Jay Leno Show." Leno was reinstated as the "Tonight Show" host, where he remains to this day, although the late night market is substantially certainly more crowded now -- "Jimmy Kimmel Live" beat "The Tonight Show" in the 18-49 demo last week for the first time ever.

Below, check out Conan's first appearance on Letterman's show. They've come a long way since Conan was rejected as a staff writer for Letterman after graduating from Harvard.