Twenty years ago the world's first webcam was created - and it was pointed at a pot of coffee. A camera was set up because computer scientists wanted to be able to see if a coffee pot in a room at Cambridge University was was full and fresh - or empty - and thus not worth a journey to the room where the coffee pot was kept. Soon computer geeks around the world were checking it daily.

Lee Harvey Oswald, the man accused of killing President John F Kennedy in November 1963 had spent more than two years living in the USSR. He had defected there after serving as a US Marine.

Photo: Associated Press, Lee Harvey Oswald in police custody.

In November 1969 the first President of Uganda, Edward Mutesa, died in exile in London.

He had been forced to flee his homeland by Milton Obote.

He died in a small flat in Bermondsey - and his friends still dispute the reasons for his death.

Photo: The Kabaka Edward Mutesa II with Pope Pius XII in 1951. AFP/GettyImages

In November 1992, a fire devastated Windsor Castle - a symbol of the British monarchy and Queen Elizabeth's weekend home. Coming at the end of a year of family problems, the blaze upset the Queen deeply and led her to declare 1992 her "Annus Horribilis".

Sir Hugh Roberts, one of the Queen's art experts, recalls the fire and the five-year project to restore Windsor Castle to its former glory.

PHOTO: Press Association.

In November 1971 a young American artist decided to get a friend to take a shot at him. His name was Chris Burden and the shooting would go down in the history of performance art. He has been speaking to Witness about the ideas behind the event.

In the 1960s, a wave of strikes and protest marches by Mexican-American farm-workers inspired Latinos across the US.

The movement was led by Cesar Chavez - a man now regarded by his community as a civil rights hero.

Witness speaks to Dolores Huerta, who worked closely with Chavez and coined the slogan "Yes We Can!"

In the 1970s the Filipino government annouced they had discovered a group of cave dwellers who were still living as people did in the stone age. But the tribe turned out to be a hoax that fooled the scientific community.

Photo: Members of the Tasaday tribe photographed by Oswald Iten in the 1980s after they admitted the hoax.

A Chinese government think tank has recommended bringing an end to the one-child policy.

It was launched in the late 1970s to tackle China's expanding population.

Hear from one woman about her personal experience of the one-child programme.

Photo: Reuters.

It's 27 years since more than 20,000 people died when a volcano erupted in western Colombia. The town of Armero disappeared under tonnes of mud, lava and water. Gilma Murillo was among the survivors. She spent 18 hours clinging onto a tree.

Photo: Gilma Murillo today.

In 1984 doctors in California tried a revolutionary operation on a two-week-old baby girl. She had been born with a fatal heart condition - but there was no infant human donor available. Hear from the lead surgeon, and an intensive care nurse involved in the fight to save Baby Fae's life.

Photo: Baby Fae listening to her mother's voice in the isolation unit. Courtesy of Loma Linda Hospital