“You don’t want to live in a world without Muhammad Ali,” George Foreman said of his former adversary. “It’s horrible.”

“The sadness,” wrote the soccer legend Pele in an Instagram post, “is overwhelming.”

Ali was hospitalized Thursday in Scottsdale, Arizona. with respiratory issues and passed away a day later. In a statement announcing Ali’s death, family spokesman Bob Gunnell said a funeral would be held in Ali’s hometown of Louisville, Kentucky, adding, The “Ali family would like to thank everyone for their thoughts, prayers, and support and asks for privacy at this time.”

His death was greeted like that of a head of state, which, in a sense, he was. His classic fights in Zaire (now the Democratic Republic of the Congo), the Philippines, Japan, England, Malaysia and Germany were global events in the days before the Internet made everything a global event. A figure who transcended the boundaries of both sport and country, he may have been the greatest ambassador the United States ever employed.

“Muhammad Ali shook up the world. And the world is better for it. We are all better for it,” President Barack Obama said in a statement. “Michelle and I send our deepest condolences to his family, and we pray that the greatest fighter of them all finally rests in peace.”

Former President Bill Clinton said in a statement, “We watched him grow from the brash self-confidence of youth and success into a manhood full of religious and political convictions that led him to make tough choices and live with the consequences. Along the way we saw him courageous in the ring, inspiring to the young, compassionate to those in need, and strong and good-humored in bearing the burden of his own health challenge.”

British Prime Minister David Cameron tweeted, “Muhammad Ali was not just a champion in the ring – he was a champion of civil rights, and a role model for so many people.”

And Australian Prime Minister Malcolm Turnbull tweeted, “Athlete, civil rights leader, humanitarian, man of faith. Rest in peace.”

NBA Hall of Famer Kareem Abdul-Jabbar wrote in a Facebook post late Friday night, “Today we bow our heads at the loss of a man who did so much for America. Tomorrow we will raise our heads again remembering that his bravery, his outspokenness, and his sacrifice for the sake of his community and country lives on in the best part of each of us.”

Paul McCartney, one of few humans with whose worldwide popularity could match Ali’s, wrote in a statement posted on his website, “I loved that man. . . . Besides being the greatest boxer, he was a beautiful, gentle man with a great sense of humour.”

In Ali’s hometown of Louisville, the American flag was lowered to half-staff Saturday at City Hall, and preparations began for Ali’s funeral, the details of which had yet to be announced.

The Rev. Jesse Jackson said: “He sacrificed the heart of his career and money and glory for his religious beliefs about a war he thought unnecessary and unjust. His memory and legacy lingers on until eternity. He scarified, the nation benefited. He was a champion in the ring, but, more than that, a hero beyond the ring. When champions win, people carry them off the field on their shoulders. When heroes win, people ride on their shoulders. We rode on Muhammad Ali’s shoulders.”

Where words failed to pay proper tribute to the man who called himself “The Greatest,” people tried photos, videos, GIFs.

There he was frozen in time, standing over Sonny Liston in 1965. There he was, in the corner of the ring, bobbing his head and dodging 21 straight punches. There he was, answering interview questions with a combination of poetry and braggadocio.

In his 2004 memoir, “The Soul of a Butterfly: Reflections on Life’s Journey” – a collaboration with his daughter Hana Yasmeen Ali – Ali addressed the question of how he would like to be remembered, writing:

“I would like to be remembered as a man who won the heavyweight championship three times, who was humorous, and who treated everyone right. 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 champion for his people. And I wouldn’t even mind if folks forgot how pretty I was.”