The 32-year-old singer confirmed Monday on a Late Late Show Carpool Karaoke special that her bad blood with Swift began over backup dancers.
"It's about backing dancers," Perry told host James Corden, explaining that three of her backup dancers asked to work with Swift while she wasn't touring. "I was like, 'Yeah, of course! ... But I will be on a record cycle in about a year, so be sure to put a 30-day contingency in your contract so you can get out if you want to join me when I say I'm going back on.'"
"So that year came up, right? And I texted all of them, because I'm very close with them, and I said, 'Look, just FYI, I'm about to start,'" she recalled. "And they said, 'Alright, we're going to talk to management about it.' And they did. And they got fired. And I tried to talk to [Taylor] 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," the star said of Swift's single "Bad Blood." "I was like, 'Okay. Cool, cool, cool. That's how you want to deal with it?'"
Perry's conflict with Swift began in 2014 when Swift hinted to Rolling Stone that "Bad Blood" is about Perry. Perry told Corden that Swift "started" the feud, but said she's willing to "take the beef off the grill."
"I think personally that women together, not divided -- and none of this petty [expletive] -- women together will heal the world," the singer said.
Perry appeared to respond to "Bad Blood" last week with her new song "Swish Swish" featuring Nicki Minaj. Orange is the New Black alum Ruby Rose defended Swift by slamming the song and Perry on Twitter.