See the timeline below.
March 2015 - Zayn leaves One Direction
The band made the announcement on their Facebook account on March 25, 2015, one week after Zayn made headlines for leaving their current tour due to "stress." "After five incredible years Zayn Malik has decided to leave One Direction. Niall, Harry, Liam and Louis will continue as a four-piece and look forward to the forthcoming concerts of their world tour and recording their fifth album, due to be released later this year," the statement read.
"My life with One Direction has been more than I could ever have imagined. But, after five years, I feel like it is now the right time for me to leave the band," Zayn added. "I'd like to apologise to the fans if I've let anyone down, but I have to do what feels right in my heart. I am leaving because I want to be a normal 22-year-old who is able to relax and have some private time out of the spotlight. I know I have four friends for life in Louis, Liam, Harry and Niall. I know they will continue to be the best band in the world."
August 2015 - "Drag Me Down" is released
The now-foursome dropped their first single without Zayn on August 20, 2015. "Drag Me Down" featured an accompanying music video with Styles, Tomlinson, Horan and Payne at NASA.
Zayn gave the song his stamp of approval. "Proud of my boys the new single is sick," he tweeted.
August 2015 - 1D announces hiatus
That same month, reports surfaced that the band will be taking an extended hiatus beginning in March 2016.
November 2015 - Made in the A.M. release
In November 2015, the foursome dropped their last One Direction album, Made in the A.M., which featured fan favorites like "Olivia," "History" and "Perfect."
November 2015: Zayn's first solo interview
In his first interview after leaving the band, Zayn got real about his time in 1D. "There was never any room for me to experiment creatively in the band," he told Fader. "If I would sing a hook or a verse slightly R&B, or slightly myself, it would always be recorded 50 times until there was a straight version that was pop, generic as f---, so they could use that version. Whenever I would suggest something, it was like it didn’t fit us."
He later told Beats 1 he didn't want to be in the band in the first place."I think I always wanted to go, from the first year, really... I never really wanted to be there in the band," he said.
January 2016 - “Pillowtalk” debut solo single from Zayn
Just a few months later, Zayn unveiled his first solo single. The steamy "Pillowtalk" music video featured girlfriend Gigi Hadid as his love interest.
March 2016 - Mind of Mine release
Two months after his debut single, Zayn dropped his full-length debut album, Mind of Mine.
December 2016 - “I Don’t Want to Live Forever” with Taylor Swift
Zayn even dabbled in a few collabs. For the 50 Shades Darker film, he teamed up with Taylor Swift for the sultry "I Don't Wanna Live Forever."
December 2018 - Icarus Falls release
Following the release of singles like "Let Me" and "Sour Diesel," Zayn dropped his sophomore album, the 27-track Icarus Falls.
November 2019 - Liam Payne and Harry Styles talk Zayn exit
"I think with Zayn’s particular exit and the way he chose to go, we haven’t really heard from him since he left," Payne told GQ. "He didn’t even say goodbye, if I am being honest. It was a really sordid scenario, from our side certainly. A bit strange. It’s difficult."
In an interview with New Music Daily, Styles mirrored the sentiment. "We were sad, obviously, that someone had left, but also sad that he was not enjoying it so much that he had to leave," he said. "Because I think at the time, too, the tour and everything was going so well and everyone had kind of got to this place where everyone was kind of living in a way where they, I think, felt pretty good. It felt like everyone was kind of enjoying it."
"I'd say, in the moment, I guess the four of us became closer because we were like, 'OK, this is a hurdle that we weren't expecting,'" he continued.
March 2020 - 1D refollows Zayn on Twitter
It's unclear exactly when all of those follows happened (or when the guys had previously unfollowed Malik), but we're still waiting to see if Zayn will follow his bandmates back.