Katy Perry sings along to 'Bad Blood' at Taylor Swift's concert, years after rumors she inspired the song

Katy Perry is proving there's no "Bad Blood" between her and Taylor Swift.

The two pop stars, who were once embroiled in a years-long feud, reunited this week at one of Swift's "Eras Tour" stops in Sydney, Australia, which Perry attended with fellow singer Rita Ora.

Luckily for fans, Perry shared pics and videos of the fun Feb. 23 on Instagram. She included a photo of her and Swift smiling as they embraced. She also shared a cheeky video that showed her reacting in the audience as Swift performed her 2015 hit "Bad Blood," which is rumored to be about the "Roar" singer.

“got to see an old friend shine tonight,” the “American Idol” judge captioned her collection.

The pair's reunion is just the latest indication that all is well between Swift and Perry, who let fans know they had buried the hatchet in a big way in 2019 when Perry appeared in Swift's video for "You Need to Calm Down."

Read on to learn all about Perry and Swift's feud and friendship over the years.

October - December 2009: Taylor Swift and Katy Perry send each other birthday shoutouts

Swift and Perry were friends before they were frenemies and were frequently photographed together at music awards shows for years.

The two pop stars spoke admiringly about one another when they each sent each other cute birthday shoutouts in 2009 on the platform then known as Twitter.

“@Katyperry knows how to throw a birthday party! I would even go as far as to say it was party-licious. Best EVER. Happy bday, pretty girl!!” Swift wrote on Oct. 25, 2009 in honor of Perry’s birthday.

Less then two months later, the “I Kissed a Girl” singer was telling Swift on her 20th birthday, “HAPPY BIRTHDAY BEAUTIFUL GIRL! You deserve it all!”

Pre-2014: The feud begins when Katy Perry hires several of Taylor Swift's backup dancers

Though the origins of Swift and Perry's feud were murky at first, fans later learned that tension between the two stars sparked after Perry re-hired several of her former backup dancers — who were working at the time for Swift —  to join her on her Prismatic World Tour, which launched in May 2014.

Lockhart Brownlie, a dancer who joined Perry on her "California Dreams" tour, confirmed that he and several others left Swift's camp to work with Perry again during an interview with Australian newspaper the Examiner in December 2013.

In 2017, Perry confirmed to talk show host James Corden that her "crazy" feud with Swift began after she invited her former dancers to join her on the road again.

September 2014: Taylor Swift talks about being 'enemies' with a fellow artist who was once a friend

Swift first described having a feud with a fellow singer in a 2014 Rolling Stone interview. She did not mention Perry by name.

“She basically tried to sabotage an entire arena tour,” Swift said when discussing the inspiration behind the song “Bad Blood" on her "1989" album, which the magazine said was “about another female artist.”

“She tried to hire a bunch of people out from under me," Swift said. "And I’m surprisingly non-confrontational — you would not believe how much I hate conflict. So now I have to avoid her.”

September 2014: Katy Perry tweets a warning about a 'Regina George'

Fans believed Perry addressed Swift's comments to Rolling Stone when she tweeted, "Watch out for the Regina George in sheep's clothing..." on Sept. 9, 2014. The tweet came one day after Rolling Stone published its interview with Swift.

Regina George is, of course, the vengeful leader of a clique of high school students played originally by Rachel McAdams in the 2004 movie "Mean Girls" and, later, by Reneé Rapp in the 2024 musical movie.

May 2015: Taylor Swift releases the music video for 'Bad Blood'

Months after discussing the song with Rolling Stone, Swift released the music video for "Bad Blood" in May 2015. Fans were quick to interpret the song's lyrics to be about Perry.

"Did you have to do this?/ I was thinking that you could be trusted/ Did you have to ruin / What was shining? Now it’s all rusted," Swift sings on the track.

July 2015: Katy Perry gets involved in a Twitter argument between Taylor Swift and Nicki Minaj

Perry stepped into the fray when Swift and Minaj had a Twitter disagreement about the Grammys in July 2015.

It seemingly started when Minaj tweeted, "If your video celebrates women with very slim bodies, you will be nominated for vid of the year,” an apparent reference to Swift’s video for “Bad Blood.”

Swift responded by telling Minaj, “It’s unlike you to pit women against each other," which prompted an uneasy back-and-forth between the two recording artists, with others joining in.

Perry inserted herself into the drama, seemingly referencing her feud with Swift, by tweeting, "Finding it ironic to parade the pit women against other women argument about as one unmeasurably capitalizes on the take down of a woman..."

May 2017: Katy Perry releases ‘Swish Swish’

Perry released the single “Swish Swish” on May 19, 2017, which many critics and fans believed was retaliation for Swift's "Bad Blood." The song’s special guest star? Nicki Minaj.

"Your game is tired/ You should retire/ You’re ‘bout as cute as/ An old coupon expired/ And karma’s not a liar/ She keeps receipts," Perry sings.

May 2017: Katy Perry opens up about the feud to talk show host James Corden

After years of avoiding the subject during interviews, Perry finally addressed the feud with Swift during a "Carpool Karaoke" segment on the "Late Late Show with James Corden" in May 2017.

“Honestly, it’s really like, she started it and it’s time for her to finish it,” Perry said, confirming the feud began when she invited three of Swift's backing dancers to re-join her camp.

The “California Gurls” singer said she had attempted to talk to Swift about their problems, “but she wouldn’t speak to me.”

“I do the right thing any time that it feels like a fumble,” Perry said, adding, “It was a full shutdown, and then she writes a song about me. I’m like, ‘OK, cool, cool, cool. That’s how you want to deal with it? Karma.’”

Perry explained that she was "ready for that BS to be done."

However, she added, “there is the law of cause and effect. You do something and there’s gonna be a reaction. And trust me, daddy, there’s gonna be a reaction.”

Perry notably sang "Swish Swish" during the episode.

June 2019: Katy Perry says there is ‘peace at last’ and tags Taylor Swift on Instagram

After years of feuding, Perry indicated that she and Swift had mended their relationship on June 11, 2019, when she shared a photo on Instagram of a plate full of cookies decorated with peace signs and the words "PEACE AT LAST."

“feels good @taylorswift,” Perry captioned the image, adding a red heart emoji.

June 2019: Katy Perry makes a surprise cameo in Taylor Swift's 'You Need to Calm Down' music video

Days later, Perry surprised fans when she made a cameo in Swift’s star-studded “You Need to Calm Down” video.

The cute video, set in a candy-colored trailer park straight out of Barbieland, shows Perry dressed in a burger costume and Swift dressed as french fries. As a food fight erupts around them, the two singers spot each other, walk to meet in the middle and begin slowly dancing. Near the video's end, the duo share a meaningful embrace.

Swift posted a pair of photos showing the two women in their fast food costumes on June 17, 2019, on Instagram.

She captioned it, “A happy meal,” adding a heart emoji.

Perry shared her own snap from the video's set, referencing the pair's past feud in her caption.

“This meal is BEEF-free,” she joked.

June 2019: Taylor Swift reveals that Katy Perry (literally) extended an olive branch to her

During an interview on the U.K. radio program "Capital Breakfast" about her new album, "Lover," Swift revealed that Perry sent her a literal olive branch in an effort to make up. She also said they had been on good terms "for a while" in the lead up to Perry's music video cameo.

“(Perry) sent me a really nice note and an olive branch, like, an actual olive branch — to my tour when it started, the 'Reputation Stadium Tour,' a while ago,” Swift said. “From that point on, we’ve been on good terms.

The "Reputation" tour ran from May to November of 2018.

Later in the interview, Swift said, “We saw each other at a party and walked up to each other and hugged it out and talked about things.”

July 2020: Katy Perry tells Howard Stern she and Taylor Swift wanted to publicly reconcile as ‘an example’ to fans

During an interview with Howard Stern in July 2020, Perry said she was happy that she and Swift reconciled publicly to serve as an example to younger fans.

“What I’m so grateful for is we did get to make up publicly and got to be an example of redemption for young girls,” she said. “I always wanted the best for her and now we can talk about the best we want for each other.”

February 2024: Katy Perry attends one of Taylor Swift's 'Eras Tour' concerts in Australia

The two singers reunited in February 2024 during one of Swift's "Eras Tour" stops in Sydney, Australia.

Perry, who attended the show with fellow pop star Rita Ora and Ora's husband, Taika Waititi, posted pics and videos from the concert Feb. 23 on Instagram.

Ora also posted photos of the group hanging out with Swift and Swift's boyfriend, Kansas City Chiefs tight end Travis Kelce.

One of Perry's pics showed her and Swift posing cheek-to-cheek with smiles on their faces. The singer also included a video of herself hamming it up for the camera while Swift performed "Bad Blood" at the show.

"got to see an old friend shine tonight," Perry captioned her post, adding a heart emoji.

This article was originally published on TODAY.com