Boxing icon Muhammad Ali has passed away at the age of 74, a family spokesman announced Friday.

He was admitted to a Phoenix-area hospital earlier this week due to respiratory issues.

The athletic icon was a champion in the ring and a civil rights pioneer outside of it.

Self-proclaiming himself "The Greatest", Ali won the heavyweight championship in the 60s. He was introduced to mainstream America shortly thereafter when he refused to serve in Vietnam.

Born Cassius Marcellus Clay, Jr. in 1942, Ali converted to Islam, changing his name to Muhammad Ali.

A 3-time heavyweight champion, Ali began boxing in 1954 at only 12 years old. He won an olympic gold medal 6 years later, winning the light heavyweight competition at the Olympics games in Rome.

As Ali's fame rose, he used his platform to fight against racism in the United States, becoming a beacon in the fight against bigotry.

He retired in 1979. One year later he was diagnosed with Parkinson's Disease.

In 2005, he was awarded the Presidential Medal of Freedom from George W. Bush.

Ali spoke openly about his goal to get to Heaven. How would he do it? Spread a message of peace.

May he now rest in peace.