When Inglis approached the Royal Army Medical Corps to offer them a ready-made medical unit staffed by qualified women, the War Office told her, "my good lady, go home and sit still." It was, instead, the French government that took up her offer and established a unit in France and she led her own unit in Serbia. Inglis was involved in all aspects of the organisation of this service down to the colours of the uniform 'a hodden grey, with Gordon tartan facings'. The French hospital was based at the Abbey of Royaumont and was run by Frances Ivens from January 1915 to March 1919. Inglis had initially offered a 100-bed hospital but it grew to hold 600 beds as it coped with the severity of battles, including that on the Somme.