Donald Duart Maclean was a British diplomat and Soviet double agent who participated in the Cambridge Five spy ring. After being recruited by a Soviet agent as an undergraduate student, Maclean entered the civil service. In 1938, he was appointed as Third Secretary at the British embassy in Paris. He served in London and Washington, D.C., achieving promotion to First Secretary. He was subsequently posted to Egypt, and then was appointed head of the American Department in the Foreign Office.

Penn is a village and civil parish in Buckinghamshire, England, about 3 miles (4.8 km) north-west of Beaconsfield and 4 miles (6.4 km) east of High Wycombe. The parish's 3,991 acres (1,615 ha) cover Penn village and the hamlets of Penn Street, Knotty Green, Forty Green and Winchmore Hill. The population was estimated at 4,168 in 2019.