Nelson Mandela was a South African anti-apartheid revolutionary and politician who served as President of South Africa from 1994 to 1999. He was born in 1918 and became involved in activism through the African National Congress Youth League in 1944, advocating non-violent civil disobedience against apartheid. Mandela was imprisoned for life from the 1960s to 1990 for conspiring to overthrow the apartheid government but used his time in prison to advocate for the anti-apartheid cause. After his release in 1990, he helped end apartheid and was elected president in 1994, becoming the country's first black head of state and working to promote reconciliation between racial groups and establish a new democratic constitution.