In September 1939, the 48th South Midlands Divisional Royal Engineers HQ and two companies were based at Northgate House, Faringdon, Oxfordshire. 226 Field Company RE then moved to Stanford-in-the-Vale, and 227 Field RE moved to Longworth, Berkshire. They joined 1 Corps, BEF in France via Southampton in November 1939 under the command of Lt-Col H.E. Moore.
During the fighting withdrawal from Belgium, on 24th May 1940, 226 Field Company were temporarily attached to 145 Brigade and travelled to Cassel from Lille and Armentieres, their journey being interrupted by French artillery units sharing the roads toward Dunkirk.
2nd Section of 226 Field Regiment were diverted to nearby Hazebrouke and have a separate War Diary describing their action in support of the 1st Bucks Battalion.
Here I attach the 226 Field Company RE’s War Diary describing their involvement at Cassel 25th-30th May 1940. Although most of the Company managed to reach Dunkirk, a substantial number of men were captured and became POW:
War Diary, 226 Field Rgt RE
24th May- ‘Heard over the wireless that Germans were in Boulogne’
25th May: ‘226 Company was billetted in an orchard just outside Cassel. HQ & Sections 1&3 constructing defence works in Cassel. 27th May 07.30: British & German artillery opened fire- the Coy was situated between two batteries [this suggests they were on southerly aspect of Mont des Recollets] 08.30: Coy moved into Cassel [town] to help garrison it’. 28th May: Steenvoorde heavily bombed. 15.00: Bde orders ‘Retire to Dunkirk with transport if possible’
29th May- DUNKIRK- ‘arrived and boarded at about 13.30’