This Army Group was established in August 1916 to attack Romania from the South. In September, following significant initial success, the first invasion was temporarily halted by the Romanians and Russians, but in October 1916, Constanța was taken, and on 6 December Bucharest. The Romanians fell back to Western Moldavia and held the front line on the Eastern Carpathians and the Siret-Danube line throughout 1917 and early 1918 until the signing of the Treaty of Bucharest (1918) on 7 May 1918.