Bernard Montgomery
In early 1915, he was appointed to be brigade major training Kitchener's New Army and returned to the Western Front in early 1916 as an operations staff officer during the battles of the Somme, Arras, and Passchendaele. During this time he came under IX Corps, part of General Sir Herbert Plumer's Second Army. Because the infantry, artillery and engineers were trained together, rehearsed together, and worked together they were able to do what they were asked efficiently and without unnecessary casualties.