In December 1952, 40 non-black people walked without permits into the South African township of Germiston, near Johannesburg. They were promptly arrested by police for trespass under the country's strictly enforced race-segregation laws. The group included seven white people, among them our father, Percy Cohen, who has died aged 90.
It was to be the first time white South Africans were imprisoned for joining an organised protest against the apartheid state. Manilal Gandhi, son of Mahatma, and Patrick Duncan, son of a former governor-general of South Africa, also took part in the Germiston trespass, and the resulting publicity drew worldwide attention to the struggle of South Africa's oppressed majority.
Percy was a quiet man who refused to accept a quiet life. His next brush with the law came a year later when he organised a children's camp at Wilgespruit, a farm west of Johannesburg. The event would have been unremarkable enough in any other country, but in South Africa it amounted to sedition because the children were drawn equally from the black, white, "coloured" (another official apartheid racial category) and Indian communities.
Two years of house arrest followed, which meant Percy missed the landmark adoption of the Freedom Charter at Kliptown in 1955 and subsequent mass Treason Trial in 1956. He was therefore free to stand for the Johannesburg municipal elections in 1957, polling a creditable 15% among an all-white electorate on a racial equality ticket.
In 1960 the South African government declared a state of emergency following the infamous Sharpeville massacre. A 4am raid led to Percy being hauled back to prison. While incarcerated, he joined a hunger strike, demanding that the women who had been rounded up should be charged or released. After nine days, these demands were met.
He was himself released after three months, and shortly after marrying our mother, Sheila, on Christmas Day 1960, was issued with a one-way exit permit to the UK. In Britain, he made his living as a dentist by day, and dedicated himself to the decades-long ANC struggle by night.
Percy was born at Evaton in the Transvaal and had trained as a dentist at the University of the Witwatersrand in Johannesburg. He was effectively the in-house dentist to Oliver Tambo (his greatest idol) and the rest of the ANC in exile, earning from them the sobriquet Painless Percy.
His long and happy retirement included supporting the ANC, even after liberation in the early 1990s, and using his professional skills to help reconstruct skulls for what is now the human origins department at the Natural History Museum in London.
He is survived by Sheila, us and four grandchildren.