Brettell was born in 1908 in Lye, West Midlands and attended the grammar school King Edward VI College, Stourbridge.[2] In 1930 he graduated with a first-class honours Degree in English at the University of Birmingham where he published his earlier poems in the University Gazette.[2] After graduating he took up a teaching position at Ruzawi School in Southern Rhodesia.[2] He returned to England in 1932 to teach at Bishop Auckland Grammar School and to enroll in a teaching diploma at the University of Birmingham and teach.[2] He returned to Southern Rhodesia permanently in 1934 and taught in government schools for the next twenty five years.[2]
His poetry appeared in several anthologies, including A Book of South African Verse (London: Oxford University Press, 1959) and P.E.N 1960: New South African Writing and a Survey of Fifty Years of Creative Achievement (1960).[2] His poems also appeared in Rhodesian Poetry, the periodical of the Poetry Society of Rhodesia (founded in 1950), New Coin, Rhodes University's poetry magazine (founded in 1964), Poetry Review Salisbury and Two Tone.[2] In an academic review (1978) of Rhodesian poetry, Graham Robin wrote that “Brettell puts into words the halting stupefaction of the exile in such a new and strange land. At last Rhodesia has a poet possessed by his country; but amazed, almost reluctantly possessed."[3]
- Bronze Frieze: Poems Mostly Rhodesian (London: Oxford University Press, 1950)
- Some Poems 1963 / The Owl and the Ivy (1963)
- Season and Festival (1965)
- One Year (1969)
- Lakeside: Sebakwe and Ngesi (1976)
- And Underfoot September (1977)
- Recessional (1981)
- Side-Gate and Stile (Harare: Books of Rhodesia, 1981)
- Molony, Rowland; David Wright; John Eppel; N.H. Brettell (1982). Four Voices: Poetry From Zimbabwe. ISBN 978-0-86920-259-3.
- Letters from England (1985)
- Eva: 1986 (1986)
- England Revisited (1990)
- Selected Poems (Cape Town: Snailpress, 1994)