Muhammad Ali recently labeled Prince Charles as "the greatest" when he welcomed the royal prince along with his second wife Camilla to his home city in Kentucky.
The former world heavyweight boxing champion's tribute came in a letter read to the Duke and Duchess of Cornwall, as they visited Louisville on the last day of their US tour, Sky News reported.
The couple was welcomed to the Kentucky Centre for African American Heritage by Louisville Mayor Greg Fischer.
Fischer read the 73-year-old boxing legend's letter, where he said that they were honoured that the royal couple had come to explore, share and learn about new sustainable initiatives that were so close to their heart.
