The German spring offensive opened on 21 March 1918 with Operation Michael and made massive gains. That afternoon CLV Bde was sent from GHQ Reserve to reinforce Third Army. It joined Guards Division reinforcing VI Corps on 23 March. The Guards took up positions in the 'Third System' of reserve trenches near Mercatel. On 25 March there was considerable German movement in front of the Guards Division, but any attempt to advance was broken up by the British artillery. However, with its flank 'in the air' VI Corps was forced to join in the general retirement during the night, pivoting on the Guards' positions. Next day the advancing German infantry and artillery presented 'splendid targets' according to the Guards' commander, and CLV Bde was in action near Hendecourt from the morning onwards. Over the next three days repeated German attacks 'withered away' in the face of rifle and shellfire, as the Guards held the pivot point around Boisleux-au-Mont and Boisleux-Saint-Marc. On 28 March the Germans renewed their efforts against this northern hinge of the British line around Arras. However, the German CB fire was inadequate and the British guns contributed to halting the German attack. A further attempt on 30 March was met by all batteries on the Guards' front firing on the 'SOS' lines with occasional 'rakes' of enemy-occupied villages: the attackers offered 'fine targets' for the guns. At the end of the day the Guards still held their positions. With this failure the German attacks on this sector had ended by 31 March.