The bishops of South Africa offered their sympathy Tuesday for the death of the controversial anti-apartheid activist and politician Winnie Madikizela-Mandela, who was the former wife of Nelson Mandela.

Madikizela-Mandela died in hospital in Johannesburg Monday at the age of 81 after a long-term illness. In an April 3 statement, the South African bishops’ conference praised her as a “committed activist [and a] courageous leader.”

Her presence as a world figure enabled her to speak “where millions of other women could not,” and “her courage, her thirst for justice for all, black and white, her inspired and persistent defiance towards an unjust system was historic and will inspire many in the future,” the message stated.

The bishops also noted that Madikizela-Mandela has a “complex history,” though her mistakes could be attributed to “a suffering and impetuous heart.”

They pointed out that under apartheid, the social worker witnessed every day the deep humiliations and blanket inequality of her people, which “were bound to cloud the mind.”

Madikizela-Mandela, called by some the “Mother of the Nation,” was arrested, imprisoned, and tortured in the 1960s for her public disregard for segregation laws and participation in a radical anti-apartheid youth movement in Soweto.

Like her husband of 38 years, Nelson Mandela, she was known for her tireless struggle against the injustices of apartheid, though her legacy was later clouded by accusations of corruption, as well as her own involvement in violence and torture, as carried out by her security detail, the Mandela Football Club, in the 1980s, for which she later apologized.

In the 1990s, she was also forced to step down from post-apartheid government positions over allegations of corruption, and, later, a fraud conviction.

Recently she had been awarded the Order of Luthuli, one of South Africa’s highest honors. She will be given a state burial April 14, according to Time Magazine.

The bishops’ statement, which was signed by Archbishop William Slattery of Pretoria, noted that Madikizela-Mandela “inspired a whole country” through her resistance to oppression and injustice.

“In the dark and oppressive years her resistance to apartheid was like a trumpet call to thousands not to fall but to arise and press on,” it said.