Before it became a mainstay on NBC’s late night schedule, The Tonight Show was nothing more than popular local program on WNBT, New York City’s NBC affiliate. It wasn’t even called The Tonight Show. It was called The Steve Allen Show after its comical host.

Steve Allen and the birth of the late night talk show

Steve Allen’s local program was just under 40 minutes long, but the popularity of those 40 minutes with television viewers was enough to convince NBC to move the show to the network and broadcast it nationally.

And on Sept. 27, 1954, it did just that, debuting at 11:20 p.m. and running for nearly 105 minutes.

Steve Allen was the original host of Tonight, saying to that debut audience that he expected The Tonight Show to last forever. His words may have been prescient, as the show has lasted more than 60 years. But not without some turmoil, controversy and changes.

Allen, along with announcer Gene Rayburn and bandleader Skitch Henderson, stuck with the program for three years. During his tenure, Allen introduced a number of talk show tropes that are employed by hosts today, such as the monologue and the comedy sketch.

By all accounts, Allen would have stayed with the show longer, but NBC wanted him to concentrate his efforts on his Sunday night variety program, in an attempt to beat the competition – the super-popular Ed Sullivan Show.

Tonight! and Jack Paar

After Allen’s departure, NBC tried to change the Tonight format, turning the late night program into a news magazine, a bit more like its counterpart, Today.

The variety show was hosted by Jack Lescoulie, and later Al “Jazzbo” Collins.

The show was not embraced by viewers or affiliates, and the format was quickly changed back to the late night talk show format Allen helped create.

Jack Paar joined the show as its second host, and for many, Paar is as much a part of the fabric of The Tonight Show as iconic host, Johnny Carson. But Paar’s time was tarnished by an ill-fated moment in February 1960.

Growing increasingly upset when he discovered NBC censored one of his monologue jokes, Paar expressed his displeasure the very next night. After he began his monologue, Paar abruptly walked out, leaving his announcer, Hugh Downs, to fill in for the remainder of the program. Paar wasn't gone long. He returned a few weeks later. To address the elephant in the room, Paar opened the show by famously saying, "As I was saying before I was interrupted … I believe the last thing I said was 'There must be a better way to make a living than this.' Well, I've looked - and there isn't."

During his time on Tonight, Paar introduced the concept of the guest host – a fellow actor or comedian who would take on hosting duties while Paar was away. One of those guest hosts was Johnny Carson

Johnny Carson

When Paar decided to leave late night for primetime, young game show host and regular Tonight guest host Johnny Carson was chosen to sit behind the desk. (There was a span between Paar’s departure and Carson’s arrival, for contractual reason, during which a handful of guest hosts filled the time. One was Merv Griffin, who was so well-received, he later got his own daytime program, The Merv Griffin Show.)

Carson debuted his version of Tonight in October 1962, with Ed McMahon as his announcer and sidekick. He was 37 years old. The rest, as they say, is history.

Carson hosted Tonight for 30 years, turning the late night program into the most iconic late night talk show in U.S. television history. McMahon’s introduction – “Heeeeeere’s Johnny!” is often imitated, setting the stage for how late night hosts are to be introduced. Carson’s bandleader, Doc Severinsin, and his TheNBC Orchestra became rock stars in their own right.

His monologue is mythic, his golf swing iconic and his cast of characters legendary. Carson regularly performed Carnac the Magnificent, Floyd R. Turbo, Art Fern and Aunt Blabby to near standing ovations.

Carson’s final Tonight Show was on May 22, 1992. His final words: “I am one of the luckiest people in the world. I found something I always wanted to do, and I have enjoyed every single minute of it. … I can only tell you that it has been an honor and a privilege to come into your homes all these years and entertain you. And I hope when I find something that I want to do, and I think you would like me to come back, that you'll be as gracious in inviting me into your home as you have been. I bid you a very heartfelt good night.”

Caron’s final Tonight is considered one of the top Most Unforgettable Finales by TV Guide.

Leno’s First Run

Tonight’s next full-time host, Jay Leno, arrived the Monday after Carson left. He also arrived following several months of television controversy.

It all began in 1991 when NBC was deciding who would succeed Carson. Late Night host David Letterman? Or regular guest host Jay Leno?

Letterman seemed a shoe-in. Long-time host of Late Night, the talk show that followed Tonight and made Letterman a household name. Even in its 12:30 a.m. slot, Late Night was a force to be reckoned with, known for creating all kinds of water cooler talk.

But then Leno came along and shook things up in an incredibly unexpected way. He lobbied hard for the job, even sneaking into a small office at the NBC Burbank studios to await a conference call between several NBC executives in charge of making the decision.

By this time, Leno had the job – but NBC brass, under pressure by Letterman’s camp who insist the host will leave the network if he isn’t offered the job, were allegedly reconsidering. The conference call was to discuss The Tonight Show situation and what to do with the hosting job. Give it to Letterman? Or keep Leno behind the desk.

The outcome, as we know, found Leno behind the desk. (Follow the full storyline here!)

And Leno would prove to be a very popular host. Since his debut in 1992, Leno has regularly scored the highest ratings in late night, often besting Letterman’s Late Show. He also has created a slew of familiar Tonight Show tropes including his man on the street interviews and “Headlines.”

But controversy wasn’t about to leave Leno behind.

Conan O’Brien and the Second Late Night Shift

In September 2004, Leno announced that he would retire in 2009, after 17 years on Tonight NBC quickly named Late Night host Conan O’Brien as his successor.

But before O’Brien could even start thinking about his move to 11:30 p.m., Leno was cooling to the idea. In 2007, he hinted that he’d like to stick around. Flash forward another year or so – and many NBC executive stomach aches – and Leno, in fact, does – by moving away from Tonight and on to a primetime 10 p.m. talk show, The Jay Leno Show.

And Conan O’Brien debuts on June 1, 2009, as the new host of Tonight.

For awhile, things seem to go swimmingly. That is until a few weeks after Leno premieres in September 2009.

Turns out that folks don’t really want to watch Leno’s primetime show, even if it is just like his Tonight Show gig. And affiliate television stations don’t want to run it, if it’s going to cut into their cash.

So NBC hatches a scheme to bring Leno back to late night. And, just like that, the wheels fall off the bus.

As soon as NBC announces the cancellation of Leno and his return to late night, O’Brien is fit to be tied. Why? Because NBC wants to put Leno on at 11:30 p.m. and move O’Brien’s Tonight Show back to after midnight. Essentially turning back the clock seven months.

O’Brien wants nothing to do with it. In fact, he wants out of his contract completely. After much negotiating – and unprecedented fan reaction – NBC lets O’Brien go.

And less than a year after leaving Tonight, Leno returns, in March 2010. (Read the entire timeline here!)

Leno’s second retirement

Leno’s second tenure as Tonight Show host lasted nearly four years. And his second retirement began with yet another round of controversy.

This time around, Leno was regularly taking shots at NBC’s lackluster ratings and its stature in the network industry. NBC execs didn’t like it. And after a spat of emails, as well as some high level meetings, word came that NBC was not going to renew Leno’s contract in 2014.

While the weeks between late February 2013 and the beginning of April 2013 were heated, this controversy quickly quieted down. And after NBC announced Late Night host Jimmy Fallon’s appointment as new Tonight Show host, Leno’s final few months have been cordial and pleasant.

Jimmy Fallon

February 17, 2014, will see the arrival of 39-year-old Jimmy Fallon as the sixth host of The Tonight Show. While the program will likely seem similar to his Late Night show, he does arrive amid some significant changes.

The first is likely Tonight’s new executive producer, Lorne Michaels, who also executive produces Late Night for NBC. Michaels is famously known as the creator and executive producer of Saturday Night Live, on which Fallon was a cast member.

Michaels and Fallon are also bringing Tonight back to New York. Carson took the program to Burbank during his tenure.

Fallon also arrives with a strong fan base and a lot of positive press. In many ways, Fallon’s Tonight could reboot the franchise, making it once more the most popular and iconic talk show in late night.

He arrives among stiff competition, with Jimmy Kimmel Live regularly rising in ratings, and Letterman’s Late Show the true classic at 11:30.