 As the American Expeditionary Forces emboldened the Allies , Germany prepared for a final attempt to achieve a decisive victory before the US contingent on the Western Front surged further . On 21 March , a five @-@ hour artillery and gas shell barrage across a 50 @-@ mile ( 80 km ) front signified the beginning of the Battle of St. Quentin ( Operation Michael ) and the Spring Offensive in the Somme . Although roled as pioneers , the 11th King 's occupied frontline trenches near Urvillers when the attack began . Two of its companies engaged troops at Lambay Wood and Benay and the battalion 's casualties for the day exceeded 160 . The Liverpool Pals , in reserve on the 21st , hurried to the front on the 22nd to undertake localised counter @-@ attacks , with the first and largest conducted by the 19th against the village of Roupy . The battalion advanced in darkness after 0115 , uncertain of German positions , but retook the original frontline trenches unopposed . They later came under sustained attack , holding out without support until Lieutenant @-@ Colonel Peck ordered a withdrawal at about 1600 . The Germans overwhelmed the survivors , capturing the wounded Peck and many others . 
