 Gollancz was commissioned into the Northumberland Fusiliers in October 1915, although he did not see active service.In March 1916 he transferred to Repton School Junior Officers' Training Corps.Gollancz proved to be an innovative and inspiring teacher; he introduced the first civics class to be taught at an English public school and many of his students went on to become teachers themselves, including James Harford and James Darling.