The British tactical objective was to capture the German defences on the ridge, which ran from Ploegsteert Wood (Plugstreet to the British) in the south, through Messines and Wytschaete to Mt Sorrel, depriving the German 4th Army of the high ground. The ridge gave commanding views of the British defences and back areas of Ypres to the north, from which the British intended to conduct the Northern Operation, an advance to Passchendaele Ridge and then capture the Belgian coast up to the Dutch frontier. The Second Army had five corps, three for the attack and two on the northern flank, not part the operation; XIV Corps was available in General Headquarters reserve. The 4th Army divisions of Group Wytschaete (, the IX Reserve Corps headquarters) held the ridge and were later reinforced by a division from Group Ypres ().