With assets being moved between Polforce and Macforce, the division was unable to fight as a cohesive entity. The divisional history, written by division staff, stated the brigades fought "confused, independent and one‐sided" battles. Most notably, they record the 137th Brigade suffering "grievous casualties" when German forces broke through their positions on the La Bassée Canal. Meanwhile, with the BEF surrounded and the military situation in Flanders having deteriorated, the decision was made to evacuate the BEF from Dunkirk, the only remaining port in British hands. The remnants of the division's brigades retreated north towards the port. On 29 May, the division was assigned to defensive positions along the Canal de Bergues and Nieuwpoort-Dunkirk Canal, on the Dunkirk perimeter. On 1 June, the division faced a major German attack, which involved bitter fighting, artillery barrages and heavy casualties. During the day, the division withdrew into Dunkirk and was subsequently evacuated via the mole or from the beaches. The 2/4KOYLI, the 2/6DWR, and the 2/7DWR had become separated from the division during the move from Rennes and were located on the southern side of the German advance into France. As they were unable to retreat towards or evacuate from Dunkirk, these battalions retreated west across France, with the 2/4KOYLI being heavily engaged in the defence of bridges crossing the Seine at Pont-de-l'Arche. These battalions eventually reached Cherbourg and Saint-Nazaire, and were evacuated as part of Operation Aerial.