All over the world, progressive people have been paying tribute to Denis Goldberg, who sadly died last month. He was a great fighter to end apartheid and for a better future for all of humankind.

In South Africa itself, the president announced that national flag was to fly at half-mast at every station in the country from May 1 to May 4 as a mark of respect and in observance of days of national mourning. I joined international voices in sending my condolences to his family, to the African National Congress (ANC), and to all the people of South Africa.

Denis was a good friend, and I had known him since he arrived in Britain in 1985. He made a great impression on me, just as he did on so many others throughout his life. He arrived in exile after spending twenty-two years in prison in South Africa, having been tried alongside Nelson Mandela, Govan Mbeki, Walter Sisulu, and others in the Rivonia Trial.

In the trial, which became known as “the trial that changed South Africa,” Denis was put up on charges of “campaigning to overthrow the government by violent revolution and for assisting an armed invasion of the country by foreign troops.” Being only thirty-one years old, he was the youngest defendant. When he and his comrades avoided the death penalty but received life imprisonment, his elderly mother did not hear the judge and asked him what he received. He shouted back: “Life — and life is wonderful!”

Denis was born in Cape Town in 1933 to Jewish parents who had relocated from Britain. He would later explain that he became aware politically as a child, saying that “I understood that what was happening in South Africa with its racism was like the racism in Nazi Germany in Europe that we were supposed to be fighting against.”

At the age of sixteen, he went to study engineering at the University of Cape Town. He became an active member of the Congress of Democrats, an organization that had links to the ANC and the South African Communist Party.

Having spent twenty-two years in prison, in which time he was only permitted to see his wife twice, he came to his new life in London after campaigning from his family led to the British government pursuing his release with the South African authorities. Once he arrived here, Denis became a spokesperson for the ANC and represented it at the Anti-Apartheid Committee of the United Nations.

When Nelson Mandela was released on February 11, 1990, Denis sat in the ITV television studio in London to comment on the live video feed that was broadcast to hundreds of TV stations around the world. I vividly remember being spellbound watching the footage of Nelson Mandela finally walking free. I thought of all those who died in the massacres at Sharpeville and Soweto, as well as all South Africans who gave their lives throughout the decades for the cause of freedom.

In London and across the entire globe, people celebrated this victory for humanity. It is a moment of history that will stay with millions forever. Denis would soon visit Nelson Mandela in South Africa, speaking for the first time since they had been sentenced. He later commented that “after the initial excitement I felt a new sense of completeness. Now all the comrades I had been sentenced with were out of prison and I had met them all.”

Like many others, I regularly visited Community H.E.A.R.T, a bookshop Denis founded on the Harvest Estate in Islington which raised funds to help improve the living standards of black South Africans. With the support of German friends, he also established Community H.E.A.R.T. e.V. in Germany in 1996.

He continued to work throughout his retirement and was honored last year with the Isitwalandwe Award — the ANC’s highest honor — for his contribution to the liberation struggle.

As one recent tribute noted, Denis had three wishes before his death: that he would die at home, that he would die in his lover’s arms, and that he would see the construction on his House of Hope begun. He died with those wishes granted (money for his final wish has been raised by the Denis Goldberg Foundation).

From a personal and political perspective, I also fondly remember a birthday talk Denis gave at South Africa House on the importance of building a South Africa for everyone, and a long conversation we had last year on the need for building a culture of international solidarity.

On both occasions, myself and others learned a lot from Denis. So too did a whole new generation of activists, who grew up since the end of apartheid; he taught them both about the horrors of apartheid and the heroic struggles of those who defeated it.

There is a beautiful synergy in that only 200 meters from where the Community H.E.A.R.T bookshop stood, we now have Steve Biko Road — a street named to permanently honor the great revolutionary. We must continue to educate new generations and carry on the struggle for global justice in honor of those who have contributed so much.

For all his years in apartheid prison, for all his sacrifices, Denis Goldberg was a man of deep humanity and generosity. It was an honor and privilege to know, and learn, from him. I am proud of our friendship and all that he taught so many of us.