(JOHANNESBURG) — South Africa’s state broadcaster says Winnie Madikizela-Mandela, prominent anti-apartheid activist and the ex-wife of Nelson Mandela, has died. She was 81. Madikizela-Mandela was married to Nelson Mandela from 1958 to 1996. Mandela was imprisoned throughout most of their marriage and Madikizela-Mandela’s own activism against the apartheid regime led to her being imprisoned for months and years under house arrest. Her political activism was marred by a kidnapping and assault conviction in 1991, for which she was fined.