Brookfield was the son of Rev. William Henry Brookfield, curate of St. Luke's, Berwick Street, and Jane Octavia, daughter of Sir Charles Elton, 6th Baronet. He was educated at Rugby School and Jesus College, Cambridge. He served as a Lieutenant in the 13th Hussars in India and retired from the regular army in 1880. He was Colonel commanding the 1st Cinque Ports VRC and was a JP for Sussex. He was appointed a Knight of Grace of the Order of the Hospital of St. John of Jerusalem in England (KGStJ) in August 1901.