In May 1916, while fighting in the Battle of Vimy Ridge, he was taken prisoner by the Germans. At the time of his capture, he held the rank of captain. He was held in Gütersloh and Krefeld, and spent his time learning languages. He was also involved in writing plays for fellow prisoners to perform, one of which was performed postwar at the Haymarket Theatre, London. He was released at the end of hostilities and returned to Britain.