© 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. The winter of 1917–1918 was a difficult time for the men and officers of the Portuguese Expeditionary Corps [C.E.P.]. Its two divisions were now fighting side by side in Flanders, but were no longer receiving regular reinforcements from Portugal, where a coup d’état had replaced the committed interventionist leadership of Afonso Costa and Norton de Matos with Sidónio Pais’ ‘New Republic’, which prioritized domestic concerns. Despite this change and an ensuing Anglo-Portuguese agreement to lessen the C.E.P.’s front, allowing only one division to remain in the trenches, the Portuguese corps in its entirety remained in situ until early April 1918 when, in the face of a looming German offensive, it began to be withdrawn. Serious questions remain regarding the timing of this withdrawal and its link to the Battle of the Lys, on 9 April, which saw the Portuguese Second Division wiped out in the course of a single morning’s fighting.