Second Battle of Oituz The Second Battle of Oituz was a confrontation between Romanian and , to a lesser extent , Russian forces on one side and German and Austro - Hungarian forces on the other , during the Romanian Campaign of World War I . The battle took place primarily in the Oituz valley in Bacău County , Romania , between August 8 and August 20 , 1917 . Prelude and order of battle . The Austro - Hungarian First Army planned to attack Romanian positions along the Oituz valley , primarily using the Gerock 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 Caṣinului , 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 ( 1st , 3rd , 6th , 7th , 9th , 12th ) and two reserve battalions . The attack would be carried out on a 7 km 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 1 – 2 km around Ungureanu peak and inflicting heavy losses on the 16th Dorobanti 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 Mount Coṣna . The Romanian 7th 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 Mărăşeşti . Only the 1st Cavalry Division arrived on August 11 , immediately entering combat and recapturing the area south of Mount Coṣna 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 " ( Mountain troops ) Battalion , after a march and a 20 - minute rest , attacked Cireşoaia peak , in tandem with the 27th Regiment and 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 Cireşoaia . On August 13 , another Romanian reinforcement , the " Grăniceri " ( Border Guards ) Brigade , attacked Central Powers positions south of the Oituz river , losing more than 800 men while gaining little ground . The 1st Cavalry Division retook Coṣna Mountain and held it against German counterattacks . At Cireşoaia , the 7th Infantry 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 .