Muhammad Ali, a former heavyweight boxing champion and 20th-century icon, has died, a family spokesperson said. He was 74.
Ali was hospitalized earlier this week in Phoenix for a "respiratory issue." The hospital stay was originally expected to be brief, but late Friday a family spokesperson announced that Ali had died.
"After a 32-year battle with Parkinson's disease, Muhammad Ali has passed away," family spokesperson Bob Gunnell said. "The three-time World Heavyweight Champion boxer died this evening."
Ali suffered from Parkinson's disease and was being treated by his doctors, Gunnell said. Ali's last public appearance was in April at a Parkinson's charity event.
Gunnell told reporters on Saturday that Ali died from septic shock due to unspecified natural causes at 9:10 p.m. MT. He said the boxing star was first hospitalized on Monday evening after falling ill, and that his family had been with him at his bedside.
A spokesperson for Laila Ali, Muhammad Ali's daughter, said her "number one priority is her father's well-being." The statement said Laila was with her father.
"She truly appreciates the outpouring of love for her family, as she spends quality time with her dad," Amber Noble Garland, Laila's spokesperson, said.
Laila also posted a photo to Facebook of her daughter, Sydney, with Ali. In the caption, Laila thanked people for their well wishes.
Another of Ali's daughters, Hana, also posted several moving photos of her father on her Instagram account.
Born Cassius Clay, Jr., on Jan. 17, 1942, in Louisville, Kentucky, Ali began boxing at a young age. In 1960, he won an Olympic gold medal in Rome, then returned to the U.S. to begin his professional career.
Ali rose to fame in the early 1960s as he racked up a series of boxing victories. He quickly built a reputation for his fighting skill and bravado. After defeating Sonny Liston — first in 1964 then again in 1965 — he became the World Heavyweight Champion.
After Ali beat Liston the first time — the bout in Miami ended with a technical knockout in the sixth round — he reportedly exclaimed "I am the greatest! I am the greatest! I'm the king of the world."
He ultimately won the heavyweight title three times and was known for his unconventional boxing style that harnessed both his speed and agility.
In 1964, after his first victory over Liston, Ali announced that he had joined the Nation of Islam. His conversion initially led him to change his name to Cassius X, but Nation of Islam leader Elijah Muhammad later gave him another name: Muhammad Ali. Ali would later refer to Cassius Clay as his "slave name."
His conversion was also polarizing among Americans, many of whom knew little of the religion at the time. He went on to convert to Sunni Islam, and later in life expressed interest in Sufism, a mystical branch of the religion.
In the years after his conversion to Islam, Ali became known for his social positions, famously refusing to be inducted into the armed forces during the Vietnam War and saying "no Vietcong ever called me nigger."
In response to his refusal to submit to the draft, Ali was stripped of his boxing title, sentenced to prison, and barred from competing. He was released on appeal but still could not box, so he turned his attention to lecturing.
In 1971, the U.S. Supreme Court reversed Ali's draft conviction.
Ali returned to boxing in the 1970s, competing repeatedly against rival Joe Frazier. Other notable bouts from this period include a fight against George Foreman in 1974 in Zaire (now the Democratic Republic of Congo) that was famously billed as "The Rumble in the Jungle," as well as two fights against Leon Spinks in 1978.
He retired from boxing in the 1980s and several years later was diagnosed with Parkinson's disease.
Following his retirement, Ali began campaigning for peace. In 1985 he traveled to Lebanon to try to secure the release of four American hostages, CNN reported. In 1990, he went to Iraq on his own and met with Saddam Hussein. He returned to the United States with 15 Americans who had been held hostage. In 1997 he was nominated for the Nobel Peace Prize.
In 1998, he was named a United Nations Messenger of Peace. "Muhammad feels that everything he did prior to now was to prepare him for where he is now in life," his wife, Lonnie Ali, said. "He is very much more a spiritual being. He is very aware of his time here on Earth. And he has sort of planned the rest of his life to do things so that he is assured a place in heaven."
At the Atlanta Olympics in 1996, Ali, his hands shaking slightly, lit the Olympic Cauldron during the Games' opening ceremony.
In 2005, Ali received his country's highest civilian honor, the presidential medal of freedom, from George W Bush.
"Far into the future, fans and students of boxing will study the films, and some will even try to copy his style," the president said in awarding Ali the medal. "But certain things defy imitation: the Ali shuffle, the lightning jabs, the total command of the ring and, above all, the sheer guts and determination he brought to every fight."
Following Ali's death, President Barack Obama and first lady Michelle Obama released a statement mourning the boxing star. The president noted that he keeps a photograph of Ali and a pair of his boxing gloves in his private study.
"Muhammad Ali shook up the world," the president said. "And the world is better for it. We are all better for it."
News of Ali's hospitalization and death prompted an outpouring of support from fans and admirers who used the hashtag #GOAT, which stands for "greatest of all time."
After Ali's death, Mayor Greg Fischer of Louisville, Kentucky — where Ali was born — ordered flags to be lowered to half staff and announced a memorial service.
"I would like to be remembered as a man who won the heavyweight title 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 a champion of his people.
"And I wouldn't even mind if folks forgot how pretty I was."
A private funeral will be held in Louisville on Thursday, followed by a Friday funeral procession and public celebration. Eulogies will be delivered by former President Bill Clinton, Bryant Gumbel, and Billy Crystal.
Ali is survived by his nine children, including daughter Laila, who like her father became a world champion boxer, and his fourth wife, Lonnie.