How does it feel to date and break up with the most famous woman alive? What happens next? Meet Joe Alwyn, a character in the Taylor Swift multiverse, written into public consciousness by the pop star and immortalized in her lyrics.

According to widely accepted readings of the primary source material, he has been The Boyfriend since 2016 — or, in Taylor-time, five albums. Walking in and out of her songs, he is the London boy she fell in love with in the pubs of his home city and behind the doors of her New York town house, where they promised to marry each other with paper rings.

But who is the real Joe Alwyn? Well, no one quite knows. The British actor, 33, is fiercely private, famously standoffish and, when it comes to fame and money, practically staid. In the six years he was together with Swift, 34, he didn’t say a word about their relationship. In the year since their breakup, still nothing, while Swift has moved from a short-lived dalliance with the 1975’s Matty Healy to an All-American love affair with NFL star Travis Kelce. But when it comes to Alwyn, it seems the quieter the man, the bigger the fiction.

Swift, swept off her feet by her Prince Charming, Travis Kelce.

This week, Swift released her 11th studio album, The Tortured Poets Department. When the title was released, Swift’s army of obsessive fans immediately drew parallels to a WhatsApp group Alwyn has with his fellow actors Paul Mescal and Andrew Scott: The Tortured Man Club. The Internet melted.

Then came the track list (“So Long, London”; “The Smallest Man Who Ever Lived”; “Guilty as Sin?”) and, earlier this month, a series of playlists published by Swift which divided up her back catalogue into the “five stages of heartbreak”, tracks previously thought of as love songs included in “denial”.

The Swifties went wild, scrapping over new bits of “evidence” which they pieced together to build a clearer picture of the man whom they are convinced is Alywn. Theories about the pair’s breakup and Alwyn’s character spread like wildfire, converted into thousands of TikTok videos and “emergency podcasts”. It is an extraordinary, terrifying scenario: the collision of modern celebrity culture with a sprawling, multiplying online web of conspiracy.

When it comes to Alwyn, it seems the quieter the man, the bigger the fiction.

Alwyn is never named in Swift’s songs, but was previously portrayed as a safe harbor amid the chaos of her fame. “I once believed love would be burning red,” sings Swift. “But it’s golden, like daylight.” Otherwise, the couple only appeared together a handful of times and, to the distress of the masses, never even uploaded a selfie, with far less of a public profile than her previous partners (Harry Styles, Calvin Harris and now Kelce).

Not satisfied, the Swift-sleuths looked for more insights into their relationship. The dates she bleached her hair were cross-referenced with lyrics written years later, put on a time line with her jet flight with his appearances at industry events, checked against leaked photographs from hacked iCloud accounts and when one or the other sounded to have a cold.

“The only Joe Alwyn we know is the Joe Alwyn [that] Swift has created,” says Jordan Pellerito, a historian at the University of Missouri who studies Swift. “And he will forever be part of the lore.”

As for the real Alwyn, he bares very little of his personal life, and portrays himself as a committed thesp who takes jobs for their theatrical merit: money, he previously said in interviews, is “dangerous” and social media is “corrosive”. He was born in Kent and grew up in Crouch End, North London, the middle of three boys. His mother Elizabeth, a psychotherapist, had a column in The Independent. His father Richard, a documentary-maker, was known for making The Shrine, about the public reaction to Princess Diana’s death.

As a teen he won a scholarship to the independent City of London School, where he was in a band, Anger Management, mostly playing heavy metal covers. “I wasn’t one of those kids who get up on the table and dance at a young age,’ he told Vogue. “But I always wanted to be an actor. I just never told anybody.”

At 18, he went to the University of Bristol, where he studied English and Theater, and after the Royal Central School of Speech and Drama. Boyishly handsome and foppish, a former classmate once said he had so much charm they called him a “quintessential pantydropper”.

Theories about the pair’s breakup and Alwyn’s character spread like wildfire, converted into thousands of TikTok videos and “emergency podcasts.”

His breakout role was in Billy Lynn’s Long Halftime Walk, getting him an invitation to the Met Gala in New York in 2016 which is where, according to clues in Swift’s lyrics, the pair might have met.

Alwyn’s life allegedly remained largely the same after they got together, living in North London and hanging out with the same group of school friends. He starred in the adaptation of Sally Rooney’s Conversations with Friends; Yorgos Lanthimos’s Oscar-winning The Favourite; and Josie Rourke’s Mary Queen of Scots, but has never quite become a leading man. In the coming year he will be in a production of Hamlet, and another Lanthimos film, Kinds of Kindness.

During lockdown, Swift and Alwyn wrote a number of songs together, which he is credited on today, but under an alias — William Bowery. It is thought he has earned $2.3 million from Spotify streams alone, as well as becoming a Grammy winner.

For many years, says Katie Su, 19, president Swift Soc at the University of the Arts, London, Alwyn was the dream boyfriend for many fans, her most sustained muse. “We grew up alongside this relationship,” she continues. “So he was part of the fandom. But as soon as they broke up people switched.” In the recent weeks “the hating has got a lot bigger”.

Some of the conclusions drawn about Alwyn by fans online are so wild I can’t write them in a newspaper, but posts on social media seem to have become increasingly violent as fans draw conclusions from public material.

And so, the fictional Joe Alwyn splits and morphs and multiplies, a garbled Frankenstein’s monster made up of pieces of the Internet. Meanwhile the real one is somewhere in North London, and couldn’t be reached for comment.

Megan Agnew is a U.K.-based features writer at The Sunday Times