With the end of hostilities on the Eastern Front and the transfer of German troops from Russia to the Western Front, the German chief-of-staff, General Erich von Ludendorff, had the resources to launch a massive offensive against the Allies. The German High Command was determined to achieve a decisive victory on the Western Front before American matériel and troops could arrive in France in large numbers.
Ludendorff launched the first offensive on 21 March 1918 and drove the British 3rd and 5th armies 40 kilometres back to Amiens. From 9 April to 15 July, the Germans carried out four more offensives. The last came to a halt with the Second Battle of the Marne from 15-17 July 1918.
The German forces employed new infiltration tactics developed by General Oscar von Hutier. The "Hutier" tactics were similar to Canadian assault tactics developed by Major-General Arthur Currie and Lieutenant-Colonel Victor Odlum. They included a "rolling barrage" that was virtually identical to the creeping barrage that the Canadian Corps first employed at Courcelette and perfected at Vimy Ridge. The German "shock troops" were small units supported by mobile light machine gun units that infiltrated British and French positions. These shock troops closely resembled Canadian trench-raiding squads. Hutier's tactical system included the use of smokescreens and gas attacks to cover the advance of German shock troops.
Significantly, Ludendorff did not launch any assaults on positions held by the Canadian Corps from 21 March to 15 July 1918. The Canadian Corps, occupying positions in the Vimy area, were not generally involved in these battles. Nonetheless, Brigadier Brutinel's Motor Machine Gun Brigade, in one of the rare instances where it was used to its full mobile potential, played a critical role plugging gaps in the crumbling British lines. In doing so, it paid a heavy price. In an interview recorded some years after the battles, Major-General Frank Worthington described the employment of the armoured cars of the "Motors" during these battles. In 1918, he was a newly commissioned officer commanding one of Brutinel's machine gun batteries. Worthington recalls:
The situation was confused and very fluid. The Germans had overcome the British defences and were now coming forward in the proper battle formations. The methods used by the Motor Machine Guns was [sic] very simple. We would take four or eight guns and open fire as the enemy was advancing, and bring him to a halt. Then the enemy would be ready to shell us out. We would move half of our guns back to a rear position -- maybe five hundred or a thousand yards back -- and as the enemy would come on with their artillery support and advance closer we would pull out the forward guns. The battle line would be cleared and the enemy would sort of collect themselves and start moving forward. Then you'd give it to them again. Day after day, it was the same thing.(Quoted in John Marteinson and Michael R. McNorgan, The Royal Canadian Armoured Corps: An Illustrated History (Toronto: Robin Brass Studio, 2000).)
The leapfrog tactics he described are, in essence, the same as those armoured units use today, a point supporting the Motors' claim as the true progenitors of modern tank and armoured reconnaissance units. Worthington would use the knowledge he gained while serving with Brutinel's machine gunners in these battles when, in 1938, he created the Armoured Fighting Vehicle School. Worthington was to be, more than any other man, responsible for dragging Canada's cavalry and embryonic tank regiments into the age of modern armoured warfare.