 He was appointed a Commander of the Royal Victorian Order (CVO) on 16 December 1911 at which time he was Inspector-General of Cavalry in India.At the outbreak of the First World War, Rimington left his staff position to accompany the Indian Expeditionary Force to France, as commander of the 1st Indian Cavalry Division.With the arrival of a second division in December 1914, he was promoted to command the Indian Cavalry Corps, remaining with it until it was disbanded.