When the British Government declared war against Germany in August 1914, a great drive to gain popular support by presenting the conflict to the public as a morally righteous endeavour began in earnest. Stories of German violence against French and Belgian civilians, largely based in fact, were central to this process of ‘cultural mobilisation’. The German soldier thus came to be widely regarded in Britain as inherently cruel and malevolent while his British counterpart was revered as the embodiment of honour, chivalry and courage. Yet within just a year of the armistice, the conduct of members of the Crown Forces in Ireland was publicly drawn into question by British commentators in a manner that would have been unthinkable during the war against Germany. Drawing on contemporary press reports, parliamentary debates, and personal narrative sources, this article explores and analyses the moral climate in Britain in 1920 and ’21 and comments on the degree to which memories of atrocities committed by German servicemen during the Great War informed popular and official responses to events in Ireland.