Simplify the following text for a Grade 9 native English-speaking person.
Original: Denis Winston Healey , Baron Healey CH , MBE , PC ( born 30 August 1917 ) is a British Labor politician , who served as Secretary of State for Defense from 1964 to 1970 and Chancellor of the Exchequer from 1974 to 1979 .
Simplified: Denis Winston Healey , Baron Healey CH , MBE , PC ( born 30 August 1917 ) is an British Labor politician . He was Secretary of State for Defense from 1964 to 1970 and Chancellor of the Exchequer from 1974 to 1979 .