Marshall was born in 1841, the son of James Marshall of Goldbeaters, Middlesex, and Catherine, daughter of Charles Morrison of Thurso.[2] He was educated at St John's School, Leatherhead,[3] and Trinity Hall, Cambridge.[2] He served in the 5th King's Royal Rifles, commanded the Huntingdonshire militia, was knighted in 1898 and was High Sheriff of Cambridgeshire and Huntingdonshire in 1890.[1] He was Mayor of Huntingdon in 1900.[2]
Marshall married Constance, daughter of William Henry Desborough of Hartford, Huntingdonshire in 1867.[2] They lived at Buckden Towers, Huntingdonshire and had three sons and one daughter.[1] His wife predeceased him in 1915.[1]