Born at Freeland, Oxfordshire, Lewis was the second son of The Rev'd Victor Arthur Nicholas Lewis, of the Dower House, Freeland, a church of England clergyman, and his wife Mary Ann, daughter of Rev.
[1] The Lewis family were minor Carmarthenshire gentry, with a strong clerical tradition alongside farming, who had made money in inn-keeping; on his father's side Lewis descended from the sailor Sir Richard Hawkins and the judge Sir William Elias Taunton, whose father, also Sir William Elias Taunton, Clerk of the Peace of Oxfordshire and Town Clerk of Oxford, bought the Freeland Lodge estate near Eynsham, Oxfordshire where Lewis was born a century later.
Shortly after his marriage, he was appointed Professor of History and English in 1934 at the Royal Naval College, Greenwich, a position he held until his retirement in 1955.
Additionally, he was lecturer in English to the Royal Navy Staff College, 1943–1957, and in Naval history, 1945–1953.
Lewis was an active member of the Navy Records Society, serving on its publication committee and council from 1938, as well as becoming vice president from 1939.