On 11th February 1990 anti-apartheid leader Nelson Mandela walked free after spending 27 years in a South African jail. It was a day that millions of black South Africans had been waiting for and marked the beginning of the end of white rule. Fellow activist Valli Moosa remembers that day, and the hasty preparations to make it possible and tells Louise Hidalgo how things almost didn't go to plan.

Picture: Nelson Mandela raises his fist in salute as he walks out of Victor Verster prison near Cape Town accompanied by his wife Winnie Mandela (Credit: Reuters/Ulli Michel)

In February 1987, a small Native American tribe from California won a landmark ruling at the US Supreme Court granting them the right to conduct gambling activities on their reservation. The campaign by the Cabazon Band of Mission Indians led to the creation of a multi-billion-dollar gaming industry on Indian land across the United States. Simon Watts talks to former Cabazon Band president, Brenda Soulliere, and their lawyer, Glenn Feldman.

PHOTO: An Indian-run casino in California (Getty Images)

In the early 1980s deaf children in Nicaragua invented a completely new sign language of their own. It was a remarkable achievement, which allowed experts a unique insight into how human communication develops. Mike Lanchin has been speaking to American linguist Judy Shepard-Kegl, who documented this process and says "our belief is that you are born with a language-ready brain".

(Photo credit should read INTI OCON/AFP via Getty Images)

The Empress Dowager Cixi ruled China for 47 years until her death in 1908. But it wasn't until the 1970s that her story began to be properly documented. She'd been vilified as a murderous tyrant, but was that really true or was she a victim of a misogynistic version of history? Prof Sue Fawn Chung was the first academic to go back to study the original documents, and found many surprises. She tells Rebecca Kesby the story of "the much maligned Empress Dowager".

(Photo: Chinese Empress Dowager Cixi, portrait c1900. Credit: Ullstein bild/Getty Images)

Norwell Roberts joined the Metropolitan police in 1967. He was put forward as a symbol of progressive policing amid ongoing tensions between the police and ethnic minorities in the capital. But behind the scenes, he endured years of racist abuse from colleagues within the force. Norwell Roberts QPM spoke to Alex Last about growing up in Britain and his determination to be a pioneer in the police force.

Photo: London's first black policeman PC Norwell Roberts beginning his training with colleagues at Hendon Police College, London, 5th April 1967. (Hulton Archive/Getty Images)

The treaty which established the European Economic Community was signed by six countries in 1957 - France, West Germany, Belgium, Italy, Luxembourg and the Netherlands. It was hoped that European countries would never go to war again, if they were tied together by economic interests. The treaty formed the basis for what is now the European Union.

Photo: European leaders at the Palazzo dei Conservatori in Rome. Credit: Keystone/Getty Images

Madam C. J. Walker was the first ever self-made female millionaire. She was born to former slaves in the USA and was orphaned at seven but against all the odds she went on to create her own business selling black hair-care products. By the time of her death in 1919 she'd become a famous philanthropist and civil rights campaigner. Claire Bowes has been speaking to her great great granddaughter A'Lelia Bundles.

Photo: Madam Walker Family Archives/A'Lelia Bundles

The remarkable Turner's oak in Kew Gardens in London not only survived the Great Storm that ravaged the south of England in 1987, but also changed the way that trees are cared for around the world.

Alejandra Martins has been speaking to Tony Kirkham, head of the Arboretum at Kew. (Photo: Turner's oak. Credit: Alejandra Martins)

In January 2013 the Indian government began to overhaul the country's laws on rape following the brutal gang rape and killing of a 23 year old physiotherapy student in Delhi. The public outcry across India forced the government to commission a legal review. Farhana Haider has been speaking to Gopal Subramanium, one of the three senior lawyers tasked with reforming the way India tackled violence against women.

(Photo: Justice Leila Seth. Justice J Verma and Justice Gopal Subramanium and team deliver their report. January 2013. Credit: Permission of Gopal Subramanium)

Prince Harry and Meghan’s announcement that they will step back from their royal duties is not the first time the British royal family has tried to reform itself from within. In 1992 Queen Elizabeth had what she called her “annus horribilis” . It was the year that her sons Prince Charles and Prince Andrew both separated from their wives, while her daughter Princess Anne got divorced - and it was also the year that Windsor Castle caught fire. The Way Ahead group was set up by senior members of the royal family and some of their closest advisors to make sure that Britain’s monarchy stayed relevant in the modern age. Lucy Burns speaks to Charles Anson, who was the Queen’s press secretary at the time.

(Photo: Queen Elizabeth II makes her "annus horribilis" speech at London's Guildhall, November 1992. Credit: Anwar Hussein/Getty Images)