A mostly-German force, represented primarily by the 11th Bavarian Infantry Division, launched an invasion of Oltenia on 23 October, resulting in the First Battle of the Jiu Valley.

The attempt however failed, as the Romanians stopped the Germans and rolled back most of their gains in a counterattack which lasted from 27 October to 1 November.

[3]: 170 [4]: 450–454 Despite the German setback in the region, Erich von Falkenhayn decided to launch the breakthrough operation across the mountains in the same area.

The valleys elsewhere were too narrow, resulting in German defeats during attempts to make progress throughout October (see the battles of Predeal, Dragoslavele and Sălătrucu).

Among the German officers involved in this battle was Erwin Rommel, at that time serving as an Oberleutnant in command of a company within the Württemberg Mountain Battalion.

Rommel telephoned Major Theodor Sproesser [de], reporting the situation and requesting urgent reinforcements.

A few minutes later, a platoon of around 50 men under Lieutenant Hohl arrived, which Rommel deployed on his exposed left flank.

Smaller groups further to the west limited their advance through the mountains until the battle was decided by the main concentration of German forces, on the Jiu River.

The Germans continued their advance on the next day with fair success, reaching the exit of the Surduc Pass by daybreak on the 11th, where they were temporarily halted north of Bumbești.

At 7 am, after the fog had dissipated, the heavy German 210 mm howitzers started firing at the Romanian fortifications, some of which had armored cupolas.

By the night of the 13th, the Germans were astride the Jiu Valley, on a front extending from Vălari past Sâmbotin to Bârcaciu.

[4]: 453 The Germans started to properly gain new ground on 15 November, when they captured the town of Târgu Jiu, the capital of Gorj County.

In order for Falkenhyan to win a complete victory at the earliest possible moment, it was necessary to force the passes in the center of the Carpathian arc.

[14] The German semi-official comment, however, claimed that it had never been the intention of their Supreme Command to break through in the southeastern Carpathian passes, trying to make out – in reaction to their defeats in the passes south of Brassó (Brașov) and on the Moldavian frontier – that these had always been part of a maneuver which aimed at attracting and binding Romanian forces in an area away from the Jiu Valley, the place singled out for the main attack.

[4]: 435  With the eastern Carpathian passes eliminated, the southern route from Brassó (Brașov) to Bucharest and the Danube offered the greatest potential for crushing the Romanian Army.

However, the Romanians expected their enemies to choose that route, and accordingly they had constructed formidable defenses in the passes south of the city before the war started.

Taking into consideration the worsening weather and the situation of the railways, Erich von Falkenhayn decided to achieve his breakout in the westernmost mountain passes.

General Curt von Morgen, one of Falknehayn's subordinates, argued that much more of the Romanian Army could have been captured if a breakthrough would have been achieved at Câmpulung instead of the Jiu Valley.