The Tonight Show is an American late-night talk show broadcast from the NBC Studios in Rockefeller Center in New York City, the show’s original location (a tradition interrupted by decades of originating from various studios in the Los Angeles region), and it has aired on NBC since 1954. The show has been hosted by six comedians: Steve Allen, Jack Paar, Johnny Carson, Jay Leno, Conan O’Brien, Jay Leno again, and Jimmy Fallon.

The Tonight Show premiered on NBC in 1954 as Tonight, hosted by Steve Allen. Jack Paar hosted the show from 1957 to 1962, but the show’s longest-running and most famous host was Johnny Carson, who hosted the show for three decades and received six Emmys. Following Carson’s 1992 retirement, “vast quantities of brainpower, money, and column inches were devoted to the issue of who was truly best suited to carry the franchise forward.”

Except for a brief (and unpopular) switch to a magazine-type news program in 1957, the format of the show has been remarkably consistent throughout its history. In many ways resembling a variety show, The Tonight Show combines a nightly monologue by the host, comedy sketches, musical guests, and celebrity interviews, all permeated by the signature style and persona of the show’s host, thus creating a nightly topical entertainment program with a pop-culture focus.

According to en.wikipedia; britannica.com. Source of photos: internet