The shocking ending of this season’s “Downton Abbey” — shocking at least for those who managed to avoid the news when the finale was shown in Britain in December — most likely left thousands of the show’s fans mourning the loss of a beloved character and angry with the show’s creators for erasing him from their lives.

The plot twist, though, was just the latest in a long tradition of television character assassinations, many of which have elicited reactions of shock, pain, sorrow, fury and sometimes laughter from devoted watchers. “Downton’s” leading man, Matthew Crawley, played by Dan Stevens, left the series in a screech of tires on a country road on Sunday, never to return. That is, unless, some other character, perhaps his beloved Mary, steps into a shower at some future time and declares that his death was all a dream. That, of course, was the infamous solution employed by the venerable television family saga “Dallas” in the ill-conceived decision to kill off a central character, Bobby Ewing, in 1985.

Generally, though, the decision to terminate a television character means there is no going back. And while many show creators say the decision to kill off a popular character carries a risk, potentially alienating viewers, in almost every case shows survive. They often thrive, the producers say, because shaking up viewers is almost always a good thing.

The death of Matthew in “Downton” recalls many other plot developments that have taken place in the middle of successful television runs, like the heart-tugging death in 1998 of Bobby Simone, the character played by Jimmy Smits in “NYPD Blue.”