Liam Payne Shares Tribute to One Direction Bandmate Louis Tomlinson After Film Premiere: 'Saved My Life'

rune hellestad/Corbis via Getty Louis Tomlinson (left) and Liam Payne (right) in 2016

Liam Payne and Louis Tomlinson have a whole lotta' history, and on Friday, the One Direction stars saluted each other.

After attending the London premiere of Tomlinson's new documentary All of Those Voices, Payne, 29, reminisced on their time in the band and his admiration for the singer with a heartfelt Instagram post.

"Seeing the world through your eyes last night was the most beautiful thing to experience," Payne wrote, alongside a photo of the pair. "My neck hurts from how much I'm looking up to you right now. You were already my friend and brother but getting to look through that window into your world and mind just extends that respect I have for you."

Stuart C. Wilson/Getty Liam Payne and Louis Tomlinson in 2015

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Payne continued, writing that he was "sorry I was so out of my mind and I didn't do better for you" given some of the things Tomlinson has "dealt with" and "held inside."

"I feel ashamed in those moments to not be as good of a friend as you have been to me, at least I have time now and I'm me again so will try and make amends," he wrote. "I'm emotionally drained watching the movie and I only did an hour and a half, you lived it and I'm so proud of how you did it not only with amazing music but with passion and the will to get up off the canvas every time life beat you down and fight back."

"I'm so thankful to have you in my life mate. I feel so lucky and I know you know this but you were part of a small group of people that literally saved my life, you dragged me out of something so dark I've never shared it, but your approach is something I admire and aspire to so I can one day do the same."

The "Strip That Down" singer closed his post by congratulating his longtime friend — whom he joined forces with in 2010 during the formation of 1D — on "every sight you get to see, every cheer that you hear and all the love you are receiving from the world."

"You worked harder than any of us to get here and now the world gets to see that from your side… guys go watch the movie, please he deserves it and you'll learn a lot about yourself from this very special man," he concluded.

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Tomlinson, too, shared his love for the fellow "What Makes You Beautiful" singer, writing on Twitter: "Special thank you to Liam for being there for me. It means the absolute world. Love you lad!"

Jeff Kravitz/FilmMagic Liam Payne and Louis Tomlinson in 2015

At the premiere, Tomlinson spoke with Rolling Stone about the importance of his pal supporting him, explaining again that it "means the world" to him. "I didn't actually expect him to come, but he told me a couple of days ago he was coming, so really just an honor and a testament to him as a guy, definitely," he said.

Payne added that "all the boys have been there for me," referring to his other bandmates: Harry Styles, Niall Horan and Zayn Malik, as well as Tomlinson. "I've suffered a bit of a dark time in my life at the moment," he said. "Honestly, I wouldn't be here without the boys."

Styles, 29, keeps 1D close to his heart, too — literally. Just this month, the pop star revealed he "accidentally" posted an Instagram Story image of himself wearing an Up All Night Tour shirt from 2011 and 2012.

"I guess some of us have secrets," Styles said at his show in Auckland, New Zealand. "Maybe, like some people, you want to keep something to yourself, and maybe one day you will accidentally post it to your Instagram Story."