He was born on 13 June 1886 in Newcastle-upon-Tyne the son of James Peacock, a grocer, and his wife, Jane Briggs.
He returned to Newcastle in 1913 to lecture in zoology at Armstrong College but this was interrupted by the First World War.
As a Territorial he was immediately called up, serving in the Royal Army Medical Corps in Flanders.
However, he was recalled to Britain to help training, lecturing in insect effects on troops and on trench fever, under the rank of captain.
Another of their children was the noted economist and academic Sir Alan Turner Peacock, born in 1922.