In the summer of 1915 the German armies continued the strengthening of front trenches, communication trenches and strong-points ordered by Chief of the General Staff General Erich von Falkenhayn, who on 25 January had also ordered the building of more defensive lines behind the front trench. Crown Prince Rupprecht the Sixth Army commander and some Western Front generals had objected to this policy, as an invitation to German troops to retreat rather than fight. After the experience of the Battle of Festubert, where Allied artillery had proved capable of destroying a great width of front trench, opposition had been abandoned and the work carried on as quickly as possible. In early May Falkenhayn had also ordered that a second defensive position be built behind the whole of the Western Front, to force an attacker to pause to move artillery forward into range.