[3] With the outbreak of the First World War, Cave joined the British Army and reached the rank of Second Lieutenant in the Inns of the Court Officers Training Regiment.
[8] In 1903, while still a Cambridge player, Cave was approached to join the British Isles team on their tour of South Africa.
On returning to Britain, Cave continued his rugby career, leaving University and joining first-class English team Blackheath.
[11] The nest season, Cave won his one and only international cap for England, when he was selected to face Wales as part of the 1905 Home Nations Championship.
Wales scored seven tries without reply, winning 25–0, England's largest losing points margin in a Championship match until their 12–27 loss to France in 1972.