Taylor Swift and Joe Alwyn first met at 2016 Met Gala on May 2, 2016. Swift was dating Calvin Harris back then, but less than a month later they broke it off and she began a short romance with British actor Tom Hiddleston, whom she also met at the Met Gala.
Through Swift's lyricism, its assumed that meanwhile she was dating Hiddleston, Joe Alwyn became one of her closest friends, although she was developing romantic feelings for him. In early September 2016, it was reported that Swift's relationship with Tom Hiddleston came to an end.
It is presumed that Swift and Alwyn began a relationship in late September, or mid-October. Fans believe their anniversary is on September 28th, due to Taylor's lyric changing while covering "September" by Earth, Wind & Fire. She replaced "Do you remember the 21st night of September?" to "Do you remember the 28th night of September?"
Joe and Taylor's relationship has inspired many of Swift's own songs. It is the main topic of her albums "reputation" (2017) and "Lover" (2019). Three songs off her album "folklore" (2020) are also presumed to be about her relationship with him, these being "invisible string," "peace," and "the lakes".
It was revealed on Swift's documentary "folklore: the long pond studio sessions" that Alwyn co-wrote tracks "exile" and "betty" with her, under the alias William Bowery. "folklore"'s sister record, "evermore" (2020) also includes songs they have co-written together, these being "champagne problems," "coney island," and "evermore".