 Complete the following phrase:  The Matilda Mk I, A11 and Matilda II A12 infantry tanks fought together in France as part of the 1st Army Tank Brigade of the British Expeditionary Force in the Battle of France. They participated in the defence and counter-attack operation at Arras against the invasion by Nazi Germany in May 1940, temporarily discomfiting the 7th Panzer Division under Rommel. In the battle, elements of motorized SS regiment Totenkopf later to be expanded into SS-Division Totenkopfwere overrun, their standard a href3.720cm20PaK2036PaK 3637a anti-tank guns proving ineffective against the heavily armoured British Matilda tank. Rommel committed some of his armour to local counterattacks, only to find the guns of the Panzer II and Panzer 38t tanks could not penetrate the Matildas armour. Desperate to prevent a British breakthrough, Rommel ordered the divisions FlaK 18 anti-aircraft guns and field guns be formed into a defensive line and fire anti-tank and HE rounds in a last-ditch effort to stop the Matildas, and this stopped the British tanks. The attack made the German commanders nervous, and the battle is historically credited with shaking the confidence of the German High Command OKW and it may have been one of the factors for the surprise German halt on 24 May that gave the BEF the slimmest of opportunities to begin 