NEW YORK (CBS) -- David Letterman is the longest-running late night TV host in American history. Today, he marks another career milestone: two decades at "The Late Show" on CBS.
If it's Bill Murray on the late show, it must be a special occasion. Thursday night, Murray helped David Letterman celebrate twenty years behind the desk of the CBS late night mainstay.
It was August 30, 1993 when Letterman first took the stage at the Ed Sullivan Theater. Murray was his first guest then, as well and the late TV landscape was changed forever. Bill Carter, author of "The Late Shift" says, "When CBS put Letterman in that job, people have to remember, networks had tried to do this - compete with the Tonight show and it took a star as big as Letterman to do that."
For decades, the tonight show was the gold standard. And its host Johnny Carson was the comedy gate-keeper, as letterman told our own Charlie Rose last fall. He said, "Well, for a person in that situation, he meant everything. The door to being a stand-up comedy or television success was The Tonight Show, the curtains through which you passed to be on The Tonight Show."
By all accounts, letterman was Carson's heir apparent, but when NBC tabbed Jay Leno for the job, Letterman was the odd man out. What followed was wounded pride, and a golden opportunity.
Sir Howard Stringer was president of CBS and signed letterman to a $14 million contract. Stringer says, "We ended a period of weakness and turned it into a period of strength and no one has ever really argued by it. Because he stands for something and it fits. It fits the definition of CBS.
What has followed is 20 years of irreverent, zany, and award winning comedy. The Late Show has won 9 Emmys and been nominated for 64 more. And then last year, letterman was celebrated at the prestigious Kennedy Center Honors.
Band leader Paul Shaffer has been Letterman's right hand man from the very beginning. He says, "Certainly when we were at 12:30 we were the alternative. We were making fun of talk shows, ourselves included, we're still certainly doing that, but we are now the, we are the talk show I think. Dave is the first to make fun of himself."
Letterman's self-deprecation is contagious; countless celebrities and bold-faced names have come on the late show to poke fun at themselves.
There have been some serious moments too. In 2000 letterman left the show for quintuple bypass surgery. The night of his return, he offered a heartfelt thanks to his medical team.
And the man who was once the late night bad boy has even been known to dole out fatherly advice these days.
Letterman has said he doesn't see much past a 25th anniversary, but those around him aren't so sure.