Winnie Mandela is dead, aged 81.

Winnie Madikizela Mandela was wife of Nelson Mandela, South Africa's first black president and freedom fighter.

Winnie endured a tainted reputation after Mandela emerged from prison after 27 years.

In 2016, Winnie left hospital after undergoing surgery on her back. She's been in and out of hospital since that time.

Winnie went for surgery and follow-up procedure early March of 2016.

Born Nomzamo Winifred Zanyiwe Madikizela, and always known simply as "Winnie", she was married to Nelson for 38 years -- one of the most storied romances of modern history.

Most of their marriage was spent apartwith Nelson imprisoned for 27 years, leaving her to raise their two daughters alone and to keep alive his political dream under the repressive white-minority regime.

In 1990 the world watched when Nelson Mandela finally walked out of prison -- hand in hand with Winnie.

Separation

But they separated just two years later and divorced in 1996 after a legal wranglethat revealed her affair with a young bodyguard.

AFP writes that with or without Nelson, Winnie built her own role as a tough, glamourous and outspoken black activist with a loyal grassroots following in the segregated townships.

"From every situation I have found myself in, you can read the political heat in the country," she said in a biography.

Winnie was born September 26, 1936, in the village of Mbongweni in what is now Eastern Cape.

She completed university, a rarity for black women at the time, and became the first qualified social worker at Johannesburg's Baragwanath Hospital.

It was her political awakening, especially her research work in Alexandra township on infant mortality, which found 10 deaths in every 1,000 births.

"I started to realise the abject poverty under which most people were forced to live, the appalling conditions created by the inequalities of the system," she said.

Arrested

Nelson and Winnie got married in June 1958, but Mandela soon went underground, hounded by the apartheid authorities.

In October that year, Winnie was arrested for the first time at a protest by women against the pass system that restricted movements of black people in white-designated areas.

After Nelson was sentenced to life in prison in 1964, Winnie was also in and out of jail as the police hounded her in a bid to demoralise him.

Nelson Mandela died on December 5, 2013.