If you’ve seen any tabloid in recent years, you know about Taylor Swift and Katy Perry’s rivalry. After their friendship turned sour in 2013, it led to years of shady songs and bitter interviews — that is, until recently, when Perry ended the feud for good. Read on to learn everything that has gone down between the two pop stars.

Before The Breakdown

From 2009 to roughly 2012, Taylor Swift and Katy Perry appeared to be two peas in a pod. The two then-rising stars tweeted compliments back and forth, performed on stage together, and even attended each other’s birthday parties. Way back then, it seemed as though the friendship was destined to last.

Things Go South

In December 2013, an interview was released in which dancer Lockhart Brownlie described leaving Taylor Swift’s Red tour along with two other dancers in order to join Katy Perry on her Prism tour. Though seemingly inconsequential, fans have identified this as the possible initial point of conflict between the two.

Taylor Squares Up

In 2015, Taylor Swift dropped the scathing single “Bad Blood,” which seemingly threw shade at Perry for allowing their friendship to sour. When asked about the song’s inspiration, Swift had described a passive-aggressive friendship and subsequent professional rivalry that sounded eerily consistent with what her former dancer had said about Perry’s actions.

Katy Fights Back

After years of throwing shade in interviews and on social media, Perry finally released her official response to Swift’s explosive claims in the form of a song entitled “Swish Swish.” The diss track featured verses from Nicki Minaj, who had previously sparred with Swift over the 2016 VMA nominations.

The Pair Calls A Truce

After years of heated conflict, the feud finally came to an end when Perry sent an apologetic letter along with an olive branch (a universal symbol of peace) to her rival’s dressing room. Swift publicly confirmed this when she posted a picture of the gifts on her Snapchat, thanking a “Katy” in her caption.