Gonville Bromhead was born on 29 August 1845 in Versailles, France. He was the youngest child born to Maj. Sir Edmund de Gonville Bromhead, 3rd Baronet, and his wife Judith. He came from a notable military family: his great-grandfather, Boardman Bromhead, fought under Major General James Wolfe at Quebec; his grandfather, Sir Gonville Bromhead, was a lieutenant general who fought in the American Revolutionary War; his father was a veteran of the Battle of Waterloo; and his three older brothers were officers in the British Army.