In 1992, a film called Buffy the Vampire Slayer was released about a valley girl cheerleader who learned that she was destined to fight vampires. Forced to grow up and take on the responsibility of protecting the world, she accepts her fate and saves most of her friends when vampires attack her school dance. Released as a comedy, it didn't do very well in theaters, but it did gain a cult following on video. The film's writer, Joss Whedon, was unhappy with how the film turned out. He initially planned on something darker and more serious, with the comedy sharp and witty instead of campy and silly. Five years later, he did something about it.

Whedon created an original script for a TV pilot, which he sold to fledgling network The WB. The new Buffy series premiered on March 10, 1997, and ran for seven seasons, five on The WB before moving to UPN for the last two. It remains an acclaimed work of television, finding a place on numerous lists as one of the best of all time. It also helped launch numerous careers, including Whedon's, who wrote and directed the two Avengers films. Buffy also had a spin-off series, Angel, and continued its story in comic book form after the show ended.

Twenty years later, star Sarah Michelle Geller has taken to Instagram offer thanks to all who helped give and celebrate the show's lasting appeal.

20 years ago today, I had the greatest privilege to bring Buffy to your tv screens for the first time. It was a long and challenging road to get there. First the movie, then a passed over pilot presentation, and eventually a mid season time slot on a little known network. That first season, we liked to think of ourselves as the little show that could. While we knew the potential, I don’t think any of us saw the lasting impact our show would have. As an actor, you wish for that one role where you can leave your mark and forever be remembered, with Buffy I got so much more. She’s a feminist challenge to gender hierarchy. Buffy may have been the Chosen One, but I was the lucky one. Thank you to Gail Berman for always believing there was a show in that movie. Thank you to Joss Whedon, for trusting me to give life to one of the greatest female characters ever created. Thank you to David, for always being my Angel. Thank you to James for understanding that while Buffy and Spike may have been love/hate, I have nothing but love for you. Alyson, as any woman knows, you are nothing without the love and support of great female friends, so thank you for being that. Michelle, you will always hold a key to my heart. Thank you to all the incredible actors for seven seasons of amazing performances. I would be remiss if I didn't mention the incredible crew that worked tirelessly (and also really tired) to bring this show to life. And lastly, but most importantly thank you to all of you, the fans. We made this show for you, and your unwavering support has kept this show going long past our seven years. You are everything. And always remember..."if the apocalypse comes, beep me" #buffyslays20 A post shared by Sarah Michelle (@sarahmgellar) on

The people that Gellar thanks by name are David Boreanez and James Marsters, who played Buffy's two main love interests, Angel and Spike. Also Michelle Trachtenberg, who played her little sister Dawn and Alyson Hannigan who was Buffy's best friend Willow. Gail Bergman, who she mentioned first, was Executive Producer. And Whedon, of course, was Buffy's creator, as well as writer, director, and showrunner.

When Geller was cast as Buffy, she already had an Emmy Award for her work on All My Children. Since Buffy, she starred in several movies and television series, including The Grudge, Ringer, and The Crazy Ones.

Buffy the Vampire Slayer left behind a lasting impression on pop culture, and the show's girl empowering themes were an inspiration to thousands of fans. The final words Geller posted in her thank you are a quote from one of the show's very first episodes, one that perfectly captures the tone of the show. A young girl wanting a normal life, even with the fate of the world resting on her. "If the apocalypse comes, beep me."

Source: Sarah Michelle Geller