Following Romania's declaration of war against Austria-Hungary on the evening of 27 August, General Culcer's Olt-Lotru Group began advancing towards Nagyszeben through the Turnu Roșu Pass. The Olt Group consisted of two columns. The easternmost one, comprising the 1st Border Guard Regiment under Lieutenant-Colonel Gheorghe Cantacuzino, crossed the mountains to the east of the Turnu Roșu Pass, using paths known only to the locals. Through the pass itself came up the 42nd Infantry Regiment, the second column of the Olt Group, departing from Titești. The attack of the 42nd Regiment took completely by surprise the Hungarian gendarmes guarding the border, and they swiftly withdrew several miles to the north, towards the Red Tower Fortress, where they encountered soldiers from the Austro-Hungarian 44th Infantry Regiment. Together, these units stopped the advance of the Olt Group's 2nd Column. Sporadic shooting followed throughout the night, but the Romanians resumed their attack in the morning. After an entire day of fighting, they finally drove the gendarmes and soldiers north and took the village at the head of the pass.