During the First World War the National Hospital for the Paralysed and Epileptic, in Queen Square, London, then Britain's leading centre for neurology, took a key role in the treatment and understanding of shell shock. This paper explores the case notes of all 462 servicemen who were admitted with functional neurological disorders between 1914 and 1919. Many of these were severe or chronic cases referred to the National Hospital because of its acknowledged expertise and the resources it could call upon. Biographical data was collected together with accounts of the patient's military experience, his symptoms, diagnostic interpretations and treatment outcomes. Analysis of the notes showed that motor syndromes (loss of function or hyperkinesias), often combined with somato-sensory loss, were common presentations. Anxiety and depression as well as vegetative symptoms such as sweating, dizziness and palpitations were also prevalent among this patient population. Conversely, psychogenic seizures were reported much less frequently than in comparable accounts from German tertiary referral centres. As the war unfolded the number of physicians who believed that shell shock was primarily an organic disorder fell as research failed to find a pathological basis for its symptoms. However, little agreement existed among the Queen Square doctors about the fundamental nature of the disorder and it was increasingly categorised as functional disorder or hysteria.