By Christopher Rosen
June 04, 2016 at 09:31 PM EDT
Focus on Sport/Getty Images)

Boxing legend Muhammad Ali, the self-proclaimed Greatest of all-time — a title he lived up to inside the ring and outside as well — died on Friday at the age of 74.

A titan of sports and popular culture, Ali’s death was mourned on social media by celebrities from all corners, including Barack Obama, Justin Timberlake, Oprah Winfrey, Madonna, Donald Trump, Mark Wahlberg, Caitlyn Jenner, and J.K. Rowling. Words written by Ali himself have also been circulated in tribute.

“I would like to be remembered as a man who won the heavyweight title three times, who was humorous, and who treated everyone right,” Ali wrote in his 2004 memoir, The Soul of a Butterfly: Reflections on a Life’s Journey. “As a man who never looked down on those who looked up to him, and who helped as many people as he could. As a man who stood up for his beliefs no matter what. As a man who tried to unite all humankind through faith and love. And if all that’s too much, then I guess I’d settle for being remembered only as a great boxer who became a leader and a champion of his people. And I wouldn’t even mind if folks forgot how pretty I was.”

GALLERY: Muhammad Ali, A Life In Pictures

Read ahead to see more reactions from stars.