On 7 June 1917, General Plumer’s 2nd Army targeted Messines Ridge, southeast of Ypres, a German salient since 1914. Plumer intended to smash the German defences on the ridge, facilitating a subsequent advance to Passchendaele Ridge, where the Allies planned to have the Third Battle of Ypres (or Passchendaele). Plumer, a cautious tactician, used an approach called ‘bite and hold’, where instead of conducting a sweeping offensive he kept to simple and limited objectives. The 2nd Army’s five corps were split, with three conducting the main offensive, while the remaining two stayed in the northern flank. The battle commenced with the detonation of 19 mines beneath the German front line defences. This was followed by a creeping barrage of artillery and infantry, supported by tanks, cavalry and aircraft. The offensive was successful and by 14 June the Allies had advanced their front line beyond the former German line.