The Austro-Hungarian First Army planned to attack Romanian positions along the Oituz valley, primarily using the Gerok Group, which recently participated in the Battle of Mărăşti. The 8th Corps would undertake the main effort; it comprised one German and two Austro-Hungarian infantry divisions deployed between Valea Dofteanei and Măgura Cașinului, and two Austro-Hungarian cavalry divisions in reserve. In front of them, the Romanian Second Army deployed the 2nd and 4th Corps, with a total of six infantry divisions and two reserve battalions. The attack would be carried out on a front, and the Romanians were outnumbered 4 to 1. Several kilometres behind the Romanian lines was the Trotuş River valley, which led to the rear of the Romanian and Russian front; thus, a successful Central Powers offensive at Oituz could have had potentially disastrous effects for the Allied war effort in Romania.
The battle
The attack began on August 8, after a violent four-hour artillery barrage. The fortified Pravila peak, held by the Romanian 27th Dorobanṭi Regiment "Bacău", was assaulted four times by the Austro-Hungarian 70th Infantry Division, without result. The German 117th Infantry division was more successful advancing around Ungureanu peak and inflicting heavy losses on the 16th Dorobanṭi Regiment "Baia". To the south, the 10th Dorobanṭi Regiment "Putna" managed to hold its ground. During the night, the Romanian 4th Corps counterattacked in the German-held areas, taking 200 prisoners and retaking some lost ground. The following afternoon, however, the Central Powers attacked in force, taking Pravila peak and advancing near. The Romanian7th Infantry Division retreated to a new defensive line. Violent fighting continued on August 10, exhausting the Romanians, who could not reinforce their lines properly due to the concurrent fighting at Mărășești. Only the 1st Cavalry Division arrived on August 11, immediately entering combat and recapturing the area south of Coșna Hill and Stibor Hill in the evening. German units which occupied the village of Oituz were pushed back by the mountain troops and armored cars of the 2nd Corps. On August 12, the newly arrived Vânători de munte Battalion, after a march and a 20-minute rest, attacked Cireșoaia peak, in tandem with the 27th Regiment, one other Romanian and two Russian battalions. The mountain troops broke through the 70th Infantry Division's defenses, taking 417 prisoners, while suffering only 21 casualties. The Austro-Hungarian division suffered nearly 1,500 total casualties at Cireșoaia. On August 13, another Romanian reinforcement, the Grăniceri Brigade, attacked Central Powers positions south of the Oituz river, losing more than 800 men while gaining little ground. The 1stCavalry Division retook Coșna Hill and held it against German counterattacks. At Cireșoaia, the 7thInfantry Division attacked together with the Russian 2nd Infantry Division; after initial gains, the Russian 195th Infantry Regiment was repelled, and Austro-Hungarian troops threatened the Romanians' flanks. Subsequently, the advance was halted.
