Tributes flow for Muhammad Ali, ‘The Greatest of All Time'

As the world mourns the passing of Muhammad Ali, tributes to the boxing legend and civil rights activist have flowed online.  

The three-time world heavyweight champion endured a long battle with Parkinson’s disease before his death in Arizona on Friday (local time).

READ MORE: 'I am America': Muhammad Ali's fight for civil rights

Social media has since been flooded with messages as political figures, celebrities and sporting stars pay their respects the charismatic athlete, whose career and cultural impact went far beyond boxing.

READ MORE: The life and times of ‘The Greatest’

 A public procession in his hometown of Louisville will farewell the man dubbed “The Greatest” on Friday.

Read some of the tributes to the iconic boxer below.