1964–1989: Post-Rivonia Trial
In August 1964, in the aftermath of the Rivonia convictions, Sisulu was served with the first in a series of banning orders. She was banned continuously for the next 17 years, prohibited from political activity and for several years confined to effective house arrest. The Minister of Law and Order allowed her fourth ban to lapse in August 1981, and she celebrated by making an address – her first political speech since the early 1960s – at a local church's commemoration of the Women's March. The respite lasted less than a year before she was arrested and served with another banning order, her fifth, in June 1982; that order was part of a more general crackdown effected in Soweto during commemorations of the 1976 Soweto uprising.
Nonetheless, throughout this period, Sisulu remained a prominent figure in the resistance movement, notable for her focus on civic organising on a national rather than local scale. She was particularly influential in the preparations for the establishment of the United Democratic Front (UDF), a popular front against apartheid that was launched in 1983, and in a protracted campaign to revive FEDSAW. From the 1970s, she was active in the political mentorship of younger women activists such as Jessie Duarte and Susan Shabangu; Duarte later said that Sisulu's protégés considered themselves "MaSisulu's girls", and she was instrumental in the foundation of a Soweto-based underground ANC cell for women, named Thusang Basadi ("wake up women").
Sisulu's June 1982 banning order was allowed to lapse after only a year, and in July 1983 she attended meetings of the national steering committee that was preparing for the national launch of the UDF. However, on 5 August, she was arrested again at her workplace and charged with a violation of the Suppression of Communism Act. She and her co-accused, activist Thami Mali, were accused of having conspired to further the aims of the banned ANC in connection with their role in planning the funeral of Rose Mbele, an ANC Women's League Stalwart. The funeral had taken place months earlier – on 16 January 1983 in a church in Soweto – and the charges were widely viewed as a justification to detain Sisulu ahead of the UDF's launch.
Later in August, while Sisulu was awaiting trial in solitary confinement in Diepkloof, the UDF was launched. She was elected in absentia as the regional president of the UDF's Transvaal branch, and then, at the front's national launch in Mitchell's Plain on 20 August, as one of the three national co-presidents of the UDF, the others being Oscar Mpetha and Archie Gumede. Her trial began in Krugersdorp shortly afterwards, with George Bizos as her defence counsel. On 24 February 1984, in a ruling condemned by the United Nations Special Committee against Apartheid, she was convicted and sentenced to four years' imprisonment, with two years of the sentence suspended for five years. However, she was also released on bail pending an appeal, allowing her to resume her political activities; she said that, after several consecutive months in solitary confinement, "I came out speaking to the walls". The appeal against her sentence was ultimately upheld in 1987.
In 1983, Sisulu retired from public nursing, having reached retirement age and received her pension. The following year, in the aftermath of her criminal trial, she began work as receptionist and nursing assistant in Rockville, Soweto in the private surgery of Abu Baker Asvat, a doctor who was renowned for his humanitarianism. Although Asvat was a leading member of the Azanian People's Organisation, a rival of the UDF, the pair worked closely together; she later said that they were like mother and son, and he did not object to Sisulu's political activities, which continued in earnest.
This period was also marked by increasing tension between Sisulu and Winnie Madikizela-Mandela, Nelson Mandela's wife, whose Mandela United Football Club engaged in gangsterism and intimidation in Soweto from around 1986 onward. Because of the friendship between their husbands, Sisulu and Madikizela-Mandela had been close during their youth; arrested together in 1958, Sisulu had nursed Mandela through the near-miscarriage of her first child in a jail cell. However, in the 1980s, their relationship grew tense as Sisulu attempted to curb Mandela United's excesses. Sisulu later said that, "As a woman, I tried to pull her out of that... Winnie and I were never enemies, I tried to help her." According to historian Jonny Steinberg, other members of the community delegated Sisulu to report their concerns about Madikizela-Mandela's behaviour to the exiled ANC leadership in Lusaka, Zambia. In later years, because of their husbands' stature, the press often contrasted Madikizela-Mandela and Sisulu as opposing models of female activism, comparing Sisulu's cool-headed maturity with Madikizela-Mandela's "rage and charm".
Meanwhile, Asvat was an unpopular figure both with the state and with conservative residents of Soweto; in 1987, Sisulu was with him when he narrowly escaped a knife attack, and in December 1988, they worked without water or electricity after the supply to their surgery was cut off. On the afternoon of 27 January 1989, Asvat was fatally shot at his surgery while Sisulu was in the dispensary at the rear of the clinic; he died shortly afterwards in Sisulu's presence. She had admitted the gunmen to an appointment with Asvat earlier that day. Madikizela-Mandela and her Football Club long faced rumours of having arranged Asvat's assassination, and Sisulu was publicly drawn into those accusations in 1997 (see below).
In 1984, while Sisulu was working at Asvat's surgery and awaiting the appeal of her criminal conviction, the UDF vastly expanded its national presence through an intensive campaign of opposition to President P. W. Botha's constitutional reforms, including the Black Authorities Act, 1982 and the 1983 Constitution. The first elections to the Tricameral Parliament in August 1984 were marred by a successful UDF boycott, followed by widespread township uprisings. In a subsequent crackdown by Botha's government, Sisulu was arrested on 19 February 1985. She and 15 others were charged under the Internal Security Act with treason and incitement to overthrow the government. As the only woman accused, she was held in detention alone.
On 3 May 1985, Sisulu and her co-accused were released on bail with stringent conditions. The ensuing Pietermaritzburg Treason Trial opened on 21 October in the Natal Supreme Court with the defendants' not-guilty plea, but the charges against Sisulu and 11 others were dropped on 9 December. Sisulu told press it was "a crushing victory for us". Popular uprisings continued, and Sisulu was banned again in 1986 and in early 1988.
