Jean Trumpington was born Jean Alys Campbell-Harris in 1922, the daughter of an officer in the 7th Hariana Lancers, who became aide-de-camp to the Viceroy of India, and an American heiress. Educated privately, she left school aged fifteen having never taken an exam. With the outbreak of the Second World War, she became first a land girl and then worked in naval intelligence. After the war, she moved to New York, where she met her husband, the historian and schoolmaster, William Barker. They returned to Britain and married in 1954, when Barker took up a post at the Leys School in Cambridge, becoming headmaster in 1958. Their only son was born in 1955.

Jean Barker, as she then was, began her political career as a Cambridge City Councillor in the early 1960s, rising to become Mayor of Cambridge in 1971. In 1980 she was made a life peer, choosing the title of Baroness Trumpington of Sandwich. She served in two Conservative governments, as Parliamentary Under-Secretary of State in the Department of Health and Social Security from 1985 to 1988 and as Minister of State in the Ministry of Agriculture, Fisheries and Food from 1989 to 1992, which, at the age of sixty-nine, made her the oldest female minister ever. She was an active member of the government front bench in the House of Lords and, in November 2012, aged ninety, was the oldest-ever guest to have appeared on Have I Got News for You. Baroness Trumpington died in November 2018.