George Martin, Nancy Reagan, Ray Tomlinson, Gillian Avery

Reeta Chakrabarti on

Sir George Martin, the legendary music producer who oversaw the Beatles' phenomenal success.
Nancy Reagan, the US First Lady, who went from actor to political wife, to campaigner against drug abuse.
Ray Tomlinson, one of the pioneers of the internet, and a founder of the email system.
And Gillian Avery, historian and award-winning author of children's literature.