The History Hour

In the 1930s, a group of German-American Nazi sympathisers known as the German American Bund held rallies and summer camps across the US. Also, the lawyers who helped Serbian leader Slobodan Milosevic defend himself against war crimes charges and how vandals attacked Denmark's famous Little Mermaid Statue.

From speed-dating to gay romance, from divorce to bigamy we look at recent changes in the way society perceives love and marriage. Plus - an expert view on how to make sure your love endures.Photo: A heart hanging over Carnaby Street in London. Credit: BBC.

This week how American cities like San Francisco became safe havens for undocumented immigrants, the story of Tilikum and first recorded killing of a human by an orca whale, discovering DNA, the ship wreck that gave locals whiskey galore and Kenya's smash hit song - that got everyone singing in Swahili.(Photo: Supporters of Sanctuary Cities demonstrating in San Francisco, January 2017. Credit: AP)

Former South African police minister on ending apartheid, eyewitness to Black Hawk Down, landmark sexual harassment case in India, the last South American war and a record breaking solo trek across the Antarctic Picture: Anti-apartheid protestors demonstrate in Cape Town on the same day that President de Klerk announced the lifting of the ban on the ANC and the release of all political prisoners, including Nelson Mandela (Credit: RASHID LOMBARD/AFP/Getty Images)

On 26 January 1972 four Aboriginal men began a protest outside Parliament House in Canberra, Australia. They erected a beach umbrella on the grass and called it an 'embassy'.Plus, the murder of five lawyers in Madrid in 1977, which became a turning point in Spain's return to democracy; the invention of the microwave oven; Roald Dahl's Charlie and the Chocolate Factory; and 75 years of the BBC's longest-running programme, Desert Island Discs.

The epic mini-series about slavery in the US hit TV screens in January 1977. We hear from actor Leslie Uggams, who played the character Kizzy, recalling how "Roots" revolutionised perceptions about African-American history. Plus: when peace deal ended El Salvador's brutal civil war, the murder of prominent Turkish Armenian journalist, Hrant Dink, life in the world's largest refugee camp, and how Dungeons and Dragons came about.(Photo: Actors LeVar Burton, Todd Bridges and Robert Reed in Roots. Credit: Alamy)

In 1997, the Princess of Wales made a high-profile visit to a landmine clearance programme in Angola. Her trip is credited with boosting the campaign for a global landmine treaty signed later that year. Also, the man who rewrote the rules on transitions of power in the USA, the first woman to wear a headscarf into the Turkish parliament and the triumph of British espionage that changed the course of World War One.PHOTO: Princess Diana in Angola in 1997 (Credit: Alamy)

The early American Communists, a North Vietnamese tunneler who helped outsmart the Americans and win the war in Vietnam, plus the pyramid scheme failure in Albania which left gun-toting children on the streets. Also how five American missionaries paid the ultimate price after seeking out a remote tribe in Ecuador but left a lasting legacy, and the petition signed in Czechoslovakia which helped bring about the end of communism.Photograph: Ella and Bert Wolfe (courtesy of the Hoover Institution Archives

December 1991 saw the end of 70 years of communist rule and the collapse of the Soviet Union. We hear from two of the key signatories of the dissolution treaty, a witness to the ensuing crisis in one of the newly independent states, and from an American nuclear expert who helped clean-up the former USSR. Also, the performance artist protesting about the growing divide between rich and poor, and the first editor of Vogue magazine in Russia. Photo: The leaders of Ukraine and Belorussia, alongside Russian leader Boris Yeltsin, at the ceremony formally dissolving the USSR in December 1991, Credit: AP

The controversial death in police custody of Italian anarchist, Giuseppe Pinelli, the Irish playwright and novelist Samuel Beckett how Greece and Turkey almost came to war over a tiny rocky island in the Aegean sea, also the experimental film-maker Derek Jarman and how on Christmas day in 1968 Apollo 8 became the first spacecraft to leave the Earth's orbit and travel to the moon.Photo:Giuseppe 'Pino' Pinelli, with his wife Licia and his daughters Silvia and Claudia. Credit: The Pinelli Family.