It's fun now to go back and read "Behind The Headlines in the Leno-Letterman War." Quick example: "David Letterman had officially been offered the job as host of 'The Tonight Show.' But the terms, as explained by Ovitz, were more than a little maddening....The deal would not go into effect until May 1994. NBC was offering David Letterman 'The Tonight Show' after a 17-month waiting period. The May date, as everyone knew, coincided with the end of Jay Leno's current contract. So the implication was clear: NBC wanted to avoid paying off Jay."
But there was melodrama long before that: "On February 11, 1960, Jack Paar walked off his show....As he left his desk, he said, 'I am leaving The Tonight Show. There must be a better way of making a living than this.' Paar's abrupt departure left his startled announcer, Hugh Downs, to finish the broadcast himself." He came back a month later. But still.
And before that in 1957: "NBC changed the show's format to a news and features show, similar to that of the network's popular morning program Today....This new version of the show was not popular, resulting in a significant number of NBC affiliates dropping the show."
It's kind of like the history of a European monarchy, where chaos, screw-ups and intrigue are the normal state of things and are interrupted only occasionally by a long, peaceful, fruitful reign.