Mandela at 100: The lessons of the South African leader resonate

He spent 27 years behind bars. He was prisoner number 466/​64.

He was South Africa’s first democratically elected black president. He served from 1994 to 1999.

He did more than anyone to end South Africa’s 40-year era of segregation and oppression. He negotiated the end of apartheid with Frederik Willem de Klerk, the last South African president who served during the apartheid era.

He went to jail because he was a revolutionary, and that meant that violence was an option — a viable tactic — he could not and would not renounce.

His cell was the size of an American’s closet. It was there that he taught himself stoicism and meditation. It was there that he learned mercy, reconciliation and peace — the peace he ultimately brought to his divided country.