At the dawn of the TV era in the 1950s, Steve Allen's zany spontaneity turns `Tonight' into a hilarious and unexpected hit. In the early 1960's, it's Jack Paar's captivating, quirky personality and Johnny Carson's impeccably hip humour.

Johnny Carson deftly navigates the turbulent 1960s to elevate `The Tonight Show' into a cultural touchstone, enshrining himself as the undisputed king of late night. His success begets competition with the emergence of Dick Cavett and Merv Griffin.

As the 1980s dawn, David Letterman reinvents late night comedy for a new generation, rescuing comedian Jay Leno's nearly flamed-out career in the process. But Johnny Carson's enduring comic appeal spawns speculation over his eventual successor.

Carson's 1992 retirement touches a nation and sets off an epic late-night war between Jay Leno and David Letterman.

As the 2000s unfold, diverse voices like Chelsea Handler and George Lopez get their seat behind the late-night desk. Jon Stewart and Stephen Colbert take the news into their own hands.

Jimmy Fallon, Stephen Colbert and Trevor Noah follow in Leno, Letterman and Stewart's footsteps. New hosts James Corden, Seth Meyers, and Samantha Bee join the late-night TV ranks.