Season 5 was when it all came together for “Seinfeld.” It was no longer a cult sitcom that couldn’t crack the Nielsen ratings’ top 20, but an appointment-viewing smash that finished third for the year overall. The following year, it would become the number one show on the air.

Why did it take so long for “Seinfeld” to break through to the mainstream? For starters, it truly lived up to its reputation as a show about nothing. While we now look at the season 2 episode “The Chinese Restaurant” as one of the greatest sitcom episodes ever, NBC executives sought to bury it because they thought an entire story built around the main characters waiting for a table was too slim of a narrative to appeal to viewers. When your network doesn’t believe in your show, it’s hard to build an audience.

“Seinfeld” needed to get traction in the popular culture, which shouldn’t have been that hard to do given that its star was a big-name stand-up comic who frequently guested on “The Tonight Show Starring Johnny Carson” and “Late Night with David Letterman.” Nevertheless, the series needed to prove it was in a league with the other top sitcoms on the air, so Seinfeld and Larry David rather cannily decided to write Michael Richards’ irrepressible Cosmo Kramer into a fictional “Murphy Brown” episode as one of the title characters’ short-lived secretaries. Fortunately, series creator Diane English was a fan of “Seinfeld” and managed to convince CBS to lend out their set and star Candice Bergen to the season 3 episode “The Keys.” Considering that “Murphy Brown” was the third highest-rated show on television at this point, it’s likely many of its viewers tuned in for the crossover event.

Seinfeld and David were grateful to English, so when she asked them to guest star on her struggling new sitcom a few years later, they happily obliged.

Diane English’s “Love & War” debuted on September 21, 1992 as a vehicle for “L.A. Law” star Susan Dey, and stumbled badly with viewers and critics. Despite game performances from a terrific ensemble featuring the likes of Jay Thomas, Joanna Gleason, and Michael Nouri, the show couldn’t find its footing. So CBS and English opted to retool after the first season, which entailed firing Dey and replacing her with Annie Potts. While Potts was clearly a better fit, the show still wasn’t connecting with mainstream viewers. So English called in her favor to Seinfeld and David.

The episode titled “Let’s Not Call It Love” aired in late 1993 during that magical fifth season of “Seinfeld,” and featured a running gag about a famous author who’s been camping out at a table in Potts’ restaurant to write. The workers and regulars finally work up the courage to ask the writer what he’s working on, and he tells them he’s working on a spec “Seinfeld” script.

English then cuts to a script-cluttered office where Seinfeld and David are reading spec submissions. They come across the spec by the author, and are surprised that a big-time author has sent them a script in which Kramer sleeps with Elaine. Seinfeld chucks the script in the trash, but then concedes that it’s “different.” So he retrieves the script, and the episode fades to credits.

Alas, “Love & War” only lasted one more season. English’s career never again reached the heights of “Murphy Brown.” In fact, given that she hasn’t produced a series or film since 2008’s “The Women,” it would appear that English is retired. It would’ve been nice to see David give her a one-off cameo in “Curb Your Enthusiasm,” but that show is, quite sadly, over as of last year.