Dr Albert Hofmann accidentally discovered the hallucinatory effects of LSD in April 1943. In 1986, he told the BBC about a "terrifying" bicycle ride home from the laboratory.
On 12 April 1955, Dr Jonas Salk announced that his vaccine was safe and effective – but he refused to profit from it.
The Unabomber's campaign of violence had baffled investigators for almost two decades. The BBC reported on his arrest 30 years ago, when he "laid a trail to his own front door".
Field Marshal Bernard Montgomery died 50 years ago. In 1968, he told the BBC about the Battle of El Alamein, and his German counterpart Erwin Rommel.
Patty Hearst was abducted by a revolutionary group in 1974, as reported by the BBC. But 50 years ago, on 20 March 1976, she was found guilty of siding with her captors.
The Portland spy ring trial began on 13 March 1961. The BBC reported on a Cold War tale of espionage, adultery, exorcism – and a deceptively ordinary-looking bungalow.
In 1946, less than a year after the end of World War Two, Britain's wartime leader sounded an urgent warning about the Soviet threat to the West.
In 1957, the painter showed the BBC how he built up his pictures of industrial urban life from his imagination, and described the loneliness that informed them.
Shergar was the world's most famous stallion. When armed men seized him from an Irish stud farm on 8 February 1983, the BBC reported on a sensational true crime saga.
