In December 1980 three US Roman Catholic nuns and a layworker were abducted and murdered in El Salvador. Their work speaking out on behalf of the poor had made them targets for the country's fiercely anti-communist military. A close friend and colleague, Sister Patricia Murray, was one of the last people to see them alive.

In November 1970, Portugal launched a surprise raid on the independent West African nation of Guinea, which had been supporting liberation fighters opposed to Portuguese rule in neighbouring Guinea Bissau.

Hundreds of Portuguese colonial troops and Guinean exiles took part in the attack. They hoped to overthrow Guinea's leader, Sekou Toure.

Photo: Rebels fighting Portuguese rule in Guinea Bissau, Credit: AFP/GettyImages

In November 1943, Stalin, Roosevelt and Churchill all met together for the first time to discuss the progress of World War Two. The meeting was held in Tehran over four days.

(Photo: Joseph Stalin (left), Franklin Roosevelt (centre), Winston Churchill (right). Credit: Keystone/Hulton Archive/Getty Images)

In 1973, the campaign group Stop de Kindermoord or Stop the Child Murder launched in the Netherlands. It would change the face of the nation's infrastructure. Witness speaks to the group's chair, Maartje van Putten.

Image: Dutch National Archive.

In November 1936, a US socialite and her Chinese-American guide captured a giant panda cub in the forests of China. Ruth Harkness took the cub to the USA and kept it in her New York flat, before selling it to a Chicago zoo.

Photo: Quentin Young, the panda cub and Ruth Harkness. Courtesy of Jolly Young.

In 1993 the first webcam went online. Its camera was focused on a coffee pot so that computer scientists in Cambridge, in the UK could see if there was any coffee available. Dr Quentin Stafford-Fraser, Martyn Johnson and Paul Jardetzky explain how they developed the precursor to Skype.

On 23rd November 1963, the first episode of one of the world's best loved TV sci-fi programmes was shown.

But the BBC's debut of Doctor Who was tragically overshadowed by the assassination of US President John F Kennedy.

Lucy Burns speaks to Carole Ann Ford, who played the Timelord's grand-daughter, Susan.

Presented and produced by Lucy Burns.

First broadcast on BBC World Service November 2013.

In 1974, bombs exploded at two busy pubs in the English city of Birmingham, killing 21 people. The IRA were blamed. Witness speaks to Les Robinson, who survived the attack.

(Photo: Debris and damage from the bomb in the basement pub. Credit: Hulton Archive/Getty Images)

In November 1995, Nigeria's military government provoked international outrage when it executed the writer, Ken Saro-Wiwa, and eight other activists from Ogoniland in the oil rich Niger Delta.

(Photo: Ken Saro Wiwa at a rally in Ogoniland. Credit: Greenpeace)

Before he shot President John F Kennedy, Oswald spent two and a half mysterious years living in Minsk. We hear from two people who got to know him during his time there.

(Photo: Lee Harvey Oswald after his arrest in Dallas, Nov 22 1963. Credit: AFP/Getty Images)