Robert Nichols was about to start his second year at Oxford when the War broke out. He joined up immediately, and as given a commission as a second lieutenant in the Royal Field Artillery. He did not go to France until late June 1916, and he was only in France between late June and early August 1916, at which point he was declared permanently unfit for general or home service. He spent several months in hospital: the problem appears to be nervous rather than physical (i.e. shell shock). In 1917 he was attached to the Foreign Office and in the following year went with the British mission (Ministry of Information) to New York.
Like many of our writers, he had started to write poetry at school, and he became one of the best -known poets of the First World War; his two collections Invocation (1915) and Ardours and Endurances (1917) were highly regarded. In E.B. Osborn’s collection The Muse in Arms (1917) he had more poems reprinted than any other poet.
On 11 November 1985, he was among 16 Great War poets commemorated on a stone in Westminster Abbey’s Poet’s Corner. The inscription on was written by Wilfred Owen: “My subject is War, and the pity of War. The Poetry is in the pity.”
My information comes from Edmund Blunden’s entry in the Oxford Dictionary of National Biography; the information in the last paragraph comes from Wikipedia.