In 1909 Furse joined the
British Red Cross Voluntary Aid Detachment attached to the
Territorial Army. In 1911, she was lodging with
Lucy Cane and family at 66 Elm Park Gardens,
Chelsea. On the outbreak of the
First World War she was chosen to head the first Voluntary Aid Detachment (VAD) unit to be sent to France. Furse realised that the existing number of nurses would prove totally inadequate to deal with the enormous amount of work which might be expected, and in September 1914 she proceeded to
France with a number of assistants, these forming the nucleus of the VAD force. In January 1915 she returned to England, and the VAD work was then officially recognised as a department of the
Red Cross organisation and she was placed in charge of the VAD Department in London. She received the
Royal Red Cross and was named a Lady of Grace of the
Order of St John of Jerusalem in 1916, and was appointed a
Dame Grand Cross of the Order of the British Empire in June 1917. Although she considered it a great success being head of the Voluntary Aid Detachment, Furse was unhappy about her lack of power to introduce reforms. In November 1917, she and several of her senior colleagues resigned due to a dispute over the living conditions of the VAD volunteers and the Red Cross refusal to co-ordinate with the Woman's Army group. Furse was immediately offered the post as director of the
Women's Royal Naval Service (WRNS), this was equivalent to the rank of
rear admiral. The Royal Navy was the first of the armed forces to recruit women and since 1916 the Women's Royal Naval Service took over the role of cooks, clerks, wireless telegraphists, code experts and electricians. The women were so successful that other organisations such as the
Women's Army Auxiliary Corps (WAAC) and the
Women's Royal Air Force (WRAF) were also established. ==Post-war==