At the onset of the Romanian Campaign, starting on 27 August 1916 with the Battle of Transylvania, the Romanian 1st Army (General Ioan Culcer) consisted of six divisions, of which four comprised the I Corps (General Ioan Popovici). In the middle of September, General Culcer moved the I Corps headquarters to Nagytalmács (Tălmaciu/Talmesch). General Popovici arrived in Nagytalmács along with his staff on 16 September. Popovici had two divisions under his command at Nagyszeben (Sibiu/Hermannstadt): the 13th and the 23rd. By October, Popovici's Corps had been driven back from Nagyszeben in disarray, but was subsequently reorganized and reinforced. On 27 September, during the Battle of Nagyszeben, the Romanian 20th Division joined Popovici's forces, attacking the Germans from the south. The 20th Division was commanded by General David Praporgescu. Following the end of the battle, Popovici was relieved and Praporgescu took over the command of the I Corps. His 20th Division remained a part of the Romanian 1st Army, joining the other two divisions of the I Corps. General Praporgescu infused new courage and energy into his subordinates. However, on 13 October, Praporgescu was killed by a stray shell on a visit to the front. He was succeeded at the command of the I Corps by General Nicolae Petala.