In 1908 he settled in England.
During the First World War, Cammaerts wrote the poems that gained him the greatest audience "Belgian Poems" Published in 1915, 'New Belgian Poems', published in 1917 and 'Messines and other Poems", published in 1918.
Cammaerts also wrote "Through the Iron Bars," which was published in 1917 and was an account of the sufferings of Belgium during the World War. He wrote the preface to the poetry anthology edited by R.M. Ingersley (Russell Markand) under the title "The Glory of Belgium: A Tribute and a Chronicle", published in 1915 by Erskine Macdonald and sold in aid of the Belgian Repatriation Fund.
Emile Cammaerts married Tita Brand, a daughter of the opera singer Madame Marie Brema. Tita Brand-Cammaerts became well known during the World War for reciting her husband's patriotic poems. Cammaerts' poem "Après Anvers" ("After Antwerp"), which was first published in "The Observer" and written in French, was translated into English by his wife. With music composed by Sir Edward Elgar, re-titled "Carillon" and first performed in public on 7th December 1914 at a concert by the London Symphony Orchestra , the work was one of the greatest successes of the First World War. Cammaerts is one of British author Michael Morpurgo's Grandfathers.
Cammaert's WW1 poems, written in French and translated by his wife, Tita Branc-Cammaerts, "Belgian Poems", were published in London by John Lane, The Bodley Head in 1915 and can be read free on-line via Archive here https://archive.org/stream/belgianpoemschan00cammiala#page/n7/mode/2up
Portrait of Emile Cammaerts from the front of "Belgian Poems" drawn by British artist and sculptor Vernon Hill.