Great Britain having entered the First World War in August 1914, Knight volunteered for full-time military service and was attested in the Royal Engineers at Kingston-on-Thames on 1 November 1915.
He served on operations in France and Flanders as a Motorcyclist Corporal, mustered as despatch rider, until he returned to England to undergo officer training in 1917.
[3] Commissioned temporary Second Lieutenant, Royal Engineers, on 22 August 1917, he returned to France, where he continued to serve on operations until wounded in action in the summer of 1918, arranging signals equipment in the front line on the Somme.
"[5] Despite his keen appetite for soldiering, Knight had an unusual perspective on the war, "It was such a frightfully dressy affair ... Not only the generals, but their ADC's and all the junior staff officers wore gorget patches on their lapels.
"[6] After some months teaching at a preparatory school and a cramming establishment, Knight returned to Hertford College, Oxford in September 1920.
And – despite "strenuous opposition from some students," he founded and took temporary command of the University College (Exeter) Contingent, Senior Division, Officers' Training Corps, in November 1936.
Notwithstanding the pressures of change in his personal circumstances and academic duties, he published a major work, Cumaean Gates in 1936, of which it has been said, "Knight had little gift for sustained and coherent argument and exposition, and he could, under the influence of whatever book or article he had just been reading, write what can only be described as nonsense.
Yet he was a remarkable man, who certainly widened the knowledge and the sensibilities of readers of Virgil; and ... he had a power to stimulate and inspire which is not given to many classical scholars" (M.L.
[16] Knight (who always preferred to spell the Roman author's name as "Vergil"), helped to found, and was appointed as an honorary Joint Secretary of, the Virgil Society in 1943.
His friend Theodore Johannes Haarhoff, Professor of Classics in the University of the Witwatersrand, subsequently wrote that his visit 'was a great success although he was a difficult guest.'
When he began his Penguin Aeneid translation, T.J. Haarhoff, 'who had for years claimed spirit-contacts with Vergil himself ... now put his powers at Jack's service'... .
Cecil Day-Lewis, afterwards Poet Laureate, remembered his first meeting with him in the nineteen thirties: "a dapper, dandyish figure, a high-pitched voice — which later I was to describe as 'the sound of a demented seagull', and alternating of enthusiasm with moodiness.