But he never made a second spaceflight, the world-wide impact of his pioneer achievement was so great that he retired there and then... Gagarin died in a training flight in March 1968.
Flight reporter Maurice Smith wrote: "When I had the pleasure of meeting him I had an immediate impression of warmth and humour... I think a great many people everywhere will feel a personal loss, rather as they did for President Kennedy..."
The British Council (@BritishCouncil) is currently tweeting updates sent, in real time, 50 years after they were first recorded. At the time few details were divulged.
Some biographical details of Yuri Gagarin and why he was chosen to perform the first human spaceflight
The details of the spacecraft Vostok were revealed in April 1965 for an exhibit in the Soviet Economic Achievement Exhibition.
Earls Court Cosmos - see pictures of the blackened Vostok I capsule, from an exhibit in August 1968.
Celebrity tour brings him to the UK: Yuri Gagarin comes to Britain
The Year of the Astronauts including a profile on Yuri Gagarin.
Where were you on this day 50 years ago? Share your memories of this pioneering achievement.