Muhammad Ali, perhaps the greatest professional athlete of all-time, has died at 74 years-of-age. An Ali family-spokesman confirmed his passing Friday night to NBC News. Prior to his death, Ali had been hospitalized for several days in a Phoenix Arizona hospital due to respiratory issues.

The incomparable Ali, who was revered as much for his championing of civil-rights causes as his in-ring daring, burst onto the world scene following the 1960 Summer Olympics. It was during these Olympic Games the brash Ali captured Gold as a boxer for the United States.

Four years later, Ali (then known as Cassius Clay) “shocked the world” by defeating dreaded heavy-hitting favorite Sonny Liston for the first of his three Heavyweight World Championships.

In 1964, shortly after defeating Liston, Clay stunned his legion of fans while changing his legal-name to Muhammad Ali. This brash choice set a tone for the staunch individual and political stances that would define Ali’s legacy. While many, including rivals Floyd Patterson and Ernie Terrell refused to acknowledge Ali’s new moniker, the Louisville native’s perseverance eventually caused his name to be revered.

[Photo by Chris Ratcliffe/Getty Images]

Long after his fighting days, Ali had been diagnosed with Parkinson’s Disease as a result of his 20-plus years as a pugilist. Though the disease would eventually rob the vaunted “Louisville Lip” of his ability to rivet the masses with his silver tongued oratory, his presence remained strong as ever.

This iconic presence was forged during the turbulent late 1960’s Vietnam war era. Ali, who had refused compulsory induction into the military in 1967 due to personal reasons was stripped of his boxing license and threatened with imprisonment from 1967-1971.

Undeterred, Ali withstood governmental pressure, financial loss and public ridicule by remaining a conscientious objector to the war. As public sentiment against the Vietnam war grew, so too did Ali’s stature as a cult hero. It was with much fanfare that Ali made his triumphant ring return in August 1970, defeating contender Jerry Quarry at the famed Omni in Atlanta Georgia.

Following his professional return, Ali showed the heart of a lion in his brutal ring wars with Joe Frazier, George Foreman, Ken Norton and Leon Spinks. After becoming the youngest (22 years) and then oldest (36 years) world heavyweight champion, Ali retired in late 1981. Long considered the finest boxer of all time, Muhammad Ali’s final in-ring record was 56-5 (37 KO).

[Photo by Chris Ratcliffe/Getty Images]

As Ali bravely battled Parkinson’s disease over the final 32 years of his brilliant life, he gained status as a worldwide figure for strength, wisdom and personal courage.

Though Ali’s health had rapidly degenerated over the course of the past decade, his spirit remained strong as ever. In December of 2015, Ali blasted Donald Trump’s comments suggesting a ban on all Muslims.

Ali himself had been a devout Muslim for decades, and said the following in response to Trump’s incendiary remarks stated via HNGN News.

“I am a Muslim and there is nothing Islamic about killing innocent people in Paris, San Bernardino, or anywhere else in the world. True Muslims know that the ruthless violence of so called Islamic Jihadists goes against the very tenets of our religion.”

That was the last of many brilliant and awe-inspiring public statements from Muhammad Ali.

Ali is survived by his nine children, including former professional women’s boxing champion Laijla, and wife Yolonda Williams. Muhammad Ali will long be remembered as one of the greatest cultural icons who ever lived.

[Photo by Chris Ratcliffe/Getty Images]