Mansfield's life and work were changed by the death of her younger brother Leslie Beauchamp, known as "Chummie" to his family. In October 1915, he was killed during a grenade training drill while serving with the British Expeditionary Force in Ypres Salient, Belgium, aged 21. She began to take refuge in nostalgic reminiscences of their childhood in New Zealand. In a poem describing a dream she had shortly after his death, she wrote:
At the beginning of 1917, Mansfield and Murry separated, although he continued to visit her at her new apartment. Ida Baker, whom Mansfield often called, with a mixture of affection and disdain, her "wife", moved in with her shortly afterwards. Mansfield entered into her most prolific period of writing after 1916, which began with several stories, including "Mr Reginald Peacock's Day" and "A Dill Pickle", being published in The New Age. Virginia Woolf and her husband Leonard, who had recently set up the Hogarth Press, approached her for a story, and Mansfield presented to them "Prelude", which she had begun writing in 1915 as "The Aloe". The story depicts a New Zealand family moving house.