mˈænsfiːld wʌz ˈɛdʒuːkˌeɪɾᵻd æt ɹˈɔɪəl mˈɪlətˌɛɹi kˈɑːlɪdʒ, sˈændhɜːst, ænd wʌz kəmˈɪʃənd ˌɪntʊ ðə fˈɪfti θˈɜːd fˈʊt æz ɐn ˈɛnsaɪn ɪn wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd θˈɜːɾi fˈaɪv.
Mansfield was educated at Royal Military College, Sandhurst, and was commissioned into the 53rd Foot as an ensign in 1835.