Do you ever look around at a fight between friends, and wonder, “What happened here?”

Well, we do too. Read below for a deep dive into the beginning, fiery middle, and sweet conclusion of one of today’s most famous feuds: the beef between Katy Perry and Taylor Swift.

Friends At First

Katy Perry and Taylor Swift were famous friends before their infamous feud. In the late 2000s, the two singer/songwriters were often photographed together and seen exchanging bubbly compliments via social media. For example, in 2008, Perry and Swift were seen together at the MTV Video Music Awards with Miley Cyrus. Then in 2009, Perry declared that a Perry/Swift collaboration would “be brilliant,” and Swift attended Perry’s birthday bash. “@Katyperry knows how to throw a birthday party! I would even go as far as to say it was party-licious,” Swift tweeted in the early morning hours of Perry’s birthday.

Then in 2010, Perry surprised Swifties by making a guest appearance on Swift’s Fearless Tour. During Swift’s concert at the Staples Center in Los Angeles, Perry performed her 2008 hit “Hot N Cold” with Swift.

No one could’ve predicted what happened next.

The Beef Gets Cookin’

In September 2014, Swift was gearing up to drop her true pop record 1989. In an interview about the album that same year, Swift revealed more than just her musical inspirations. In fact, she officially debuted her feud with Perry.

“For years, I was never sure if we were friends or not,” she said. “She would come up to me at awards shows and say something and walk away, and I would think, ‘Are we friends, or did she just give me the harshest insult of my life?’”

Then, Swift explained that their beef started in 2013. “She did something so horrible,” Swift said. “I was like, ‘Oh, we’re just straight-up enemies.’ And it wasn’t even about a guy! It had to do with business. She basically tried to sabotage an entire arena tour. She tried to hire a bunch of people out from under me. And I’m surprisingly non-confrontational—you would not believe how much I hate conflict. So now I have to avoid her. It’s awkward, and I don’t like it.”

Digging the knife in just a little further, Swift stated, “But I don’t think there would be any personal problem if she weren’t competitive.”

Ouch.

Reacting quickly, just a day after the interview tell-all was published, Perry tweeted what we can only assume was meant for Swift. “Watch out for the Regina George in sheep’s clothing,” Perry tweeted.

Taking another opportunity to stand up for herself, Perry said in a 2015 interview that “[if] somebody is trying to defame my character, you’re going to hear about it.” Duly noted, Perry.

Bad Blood

Later in 2015, Swift dropped her song “Bad Blood” featuring Kendrick Lamar. Swift openly explained that the song was about the loss of a friendship rather than heartbreak. The lyrics express intense feelings of betrayal:

Now did you think it all through?
All these things will catch up to you
And time can heal, but this won’t
So if you come in my way, just don’t

Oh, it’s so sad to think about the good times
You and I.

Many speculated that “Bad Blood” was written about Perry. Including Perry herself.

Perry released her song “Swish Swish” featuring Nicki Minaj in 2017, which many speculated was Perry’s response to “Bad Blood.” In an interview with James Corden, Perry sang along to “Swish Swish” during the talk show host’s Carpool Karaoke segment before explaining her feud with Swift.

“Honestly, [Swift] started it, and it’s time for her to finish it,” Perry told Corden.

“It’s about backing dancers. It’s so crazy,” she continued. “There [are] three backing dancers that went on tour with her tour, and they asked me before they went on tour if they could go. I was like, ‘Yeah, of course. I’m not on a record cycle. Get the work. She’s great. But I will be on a record cycle, probably, in about a year, so be sure to put a 30-day contingency in your contract so you can get out if you wanna join me when I say I’m going back on.’ So that year came up, and I texted all of them because I’m very close with them. I said, ‘Look, just FYI: I’m about to start. I want to put the word out there.’ They said, ‘Okay. We’re gonna go talk to management about it.’ They did, and they got fired. I tried to talk to [Swift] about it, and she wouldn’t speak to me.”

“I do the right thing anytime that it feels like a fumble. It was a full shutdown, and then she writes a song about me. And I’m like ‘Okay, cool, cool. That’s how you wanna do it?” she said.

In response to Katy Perry’s revelation about their feud, Taylor Swift made a strategic move by deciding to re-release her catalog of music on streaming platforms. This decision came on the same day that Perry was releasing her fifth album, Witness. It was seen by many as a calculated move, especially considering Swift had previously pulled her music from streaming platforms back in 2014.