Today marks what would have been the 75th birthday of one of the 20th century’s most significant and famous athletes, Muhammad Ali.

Born Cassius Clay Jr in 1942 in the Southern U.S. state of Kentucky, Ali began his rise to fame in 1960 when he won a gold medal in the light heavyweight division of the 1960 Summer Olympics in Rome. Four years later, he truly shot to superstardom after winning the WBA, WBC, and lineal heavyweight titles. It was also during the late 1960s that he changed his name to Muhammed Ali, describing “Cassius Clay” as his “slave name”.

While most recognized for his efforts in the boxing ring, Ali was the voice behind quotes such as “float like a butterfly, and sting like a bee”. The famous boxer was also a keen activist for black Americans’ civil rights, and strongly opposed the United States’ involvement in the Vietnam conflict, making him an icon and a historical figure of the counterculture.

Ali hung up his boxing gloves in 1981, and in 1984 was diagnosed with Parkinson’s Disease, a result of decades spent in the boxing ring. Over the next 32 years, he yet again showed his fighting spirit in combatting the disease, until he passed away on June 3, 2016. On average, sufferers live between seven and 14 years after diagnosis.

To celebrate his birthday, Bored Panda has found a selection of rare photos to document Ali’s remarkable life as an athlete, an activist, and an inspiration to athletes and non-athletes alike all over the world.