In May 1940, the brigade was variously assigned to a succession of infantry divisions: 5th (4–9 May), 50th (Northumbrian) (9–18 May), 3rd (18–19 May), back to the 50th (19–21 May), 46th (21–26 May) and finally to the 2nd (26–31 May). The brigade saw action at the Battle of St Omer-La Bassée (23–29 May) before it was evacuated at Dunkirk on 31 May 1940.