The Science of Crowd Science

We look at some of the broadcasts delivered by Queen Elizabeth II including her first radio address to the children of the Commonwealth on 13 October 1940. Former BBC royal correspondent Jennie Bond looks back on the Queen's significant moments in front of a microphone.

Pope Paul VI's first visit to Africa when he travelled to Uganda in 1969, and was hosted by an Ismaili Muslim family and the start of the Iran-Iraq war in September 1980.

(Photo: Princess Elizabeth makes a broadcast from the gardens of Government House in Cape Town, South Africa, on her 21st birthday. Credit: BBC)