 Confusion had been caused by the original attacking divisions on the ridge , having control over the artillery which covered the area occupied by the reserve divisions down the eastern slope . The arrangement had been intended to protect the ridge from large German counter @-@ attacks , which might force the reserve divisions back up the slope . The mistaken bombardments of friendly troops ended late on 9 June , when the New Zealand , 16th ( Irish ) and 36th ( Ulster ) divisions were withdrawn into reserve and the normal corps organisation was restored ; anticipated large German counter @-@ attacks had not occurred . On 10 June , the attack down the Blauwepoortbeek began but met strong resistance from the fresh German 11th Division , brought in from Group Ypres . The 3rd Australian Division advanced 600 yards ( 550 m ) either side the river Douve , consolidating their hold on a rise around Thatched Cottage , which secured the right flank of the new Messines position ; early on 11 June , the Germans evacuated the Blauwepoortbeek sector . British observation from the Oosttaverne line proved to be poor , which led Plumer to order a further advance down the slope . On 14 June , the II Anzac Corps was to push forward on the right from Plugstreet Wood to Trois Tilleuls Farm and Hill 20 and another 1 @,@ 000 yards ( 910 m ) to the Gapaard spur and Ferme de la Croix . IX Corps was to take Joye Farm , the Wambeke hamlet and come level with the Australians at Delporte Farm ; X Corps was to capture the Spoil Bank and the areas adjacent . The attack was forestalled by a German retirement on the night of 10 / 11 June and by 14 June , British advanced posts had been established without resistance . 
