July 18 is Nelson Mandela‘s birthday; the late South African president and legendary anti-apartheid activist would have turned 104. His birthday has been declared Nelson Mandela International Day in his honor. As we remember his life and legacy this year, here are six things you may not have known about Mandela.

1. He was not born Nelson

The man known to the world as Nelson Mandela has had many names over the years. He was born Rolihlahla Mandela in 1918. His first name was a local saying that meant troublemaker.

At nine, he was given the name “Nelson” by a teacher, a common practice in South Africa in which children were given Christian names that were easier for white people to pronounce. After undergoing a traditional circumcision ritual to mark his transition to manhood, he was given the name “Dalibunga.” And to many people, he was affectionately known as Madiba, the name of his Xhosa clan.

2. He started South Africa's first Black law firm

Mandela studied law as a young man but was expelled from the University College of Fort Hare in 1931 after engaging in a student protest. This did not stop him from co-founding a law firm with Oliver Tambo, a fellow activist who would go on to lead the African National Congress while Mandela was imprisoned. Their firm is often considered the first Black law practice in South Africa. Mandela finally received his law degree in 1989, shortly before he was released from prison.

3. He was a major boxing fan

Mandela competed in amateur boxing tournaments in his youth and remained a fan of the sport throughout his life. “I did not enjoy the violence of boxing,” Mandela later wrote in his autobiography, “so much as the science of it.” During his 27-year-imprisonment for anti-apartheid activism, Mandela used boxing training to keep himself occupied and centered. Years later, boxing legend Sugar Ray Leonard gifted Mandela with a World Boxing Council championship belt.

4. His first time voting was the election that made him president

Despite his decades of political activism, Mandela had not been able to vote for the candidate of his choice due to the oppression of apartheid. Thus, the very first time he voted was when he was on the ballot in 1994 in the election that made him South Africa’s first Black president. Mandela cast this historic vote at Ohlange High School in the KwaZulu-Natal province of South Africa.

5. Even as President of South Africa, the U.S. officially labeled him a terrorist

During his years of activism with the African National Congress, Mandela and other ANC members were labeled communists, subversives and terrorists. Mandela was placed on a U.S. terrorist watch list and remained labeled as such during and after his presidency. His name was finally removed from the U.S. terrorist list in 2008.

6. Later in life, he served as a leader of world leaders

Mandela remained very involved in world politics throughout his life. In 2007, Mandela celebrated his 89th birthday by announcing that he was forming the Elders, an organization of world leaders. The organization, dedicated to peace and negotiations, has included U.S. President Jimmy Carter as well as late leaders including Kofi Annan and Archbishop Desmond Tutu.

On this Nelson Mandela International Day, let’s remember Mandela and his legacy, even as we learn more about his long and amazing life and career.