When it entered the First World War on August 27, 1916, Romania had a clearly defined military plan: three armies were to enter Transylvania and then advance towards the Hungarian Plain. In contrast, at the southern border with Bulgaria a single army had to initially defend, and then mount a limited offensive in the Ruse-Varna area. However, plans don’t often fit the realities on the field.

Romania was in a geostrategic nightmare on August 27, 1916. It had to fight on two fronts, but the objective was clear: the integration into the Kingdom of Romania of the Romanian inhabited provinces of Austria-Hungary. That is why the main fighting force focused on Transylvania, where three Romanian armies were deployed.

On the other hand, at the southern border with Bulgaria, the Third Army was deployed, with almost 150.000 soldiers, commanded by General Mihai Aslan, at the time of Romania’s entry into the war. According to the battle plan, called Hypothesis Z, drawn up by the Great General Headquarters, the army commanded by Aslan had to repel the eventual Bulgarian attack in the first phase, and 10 days after mobilization it had to go on the offensive to destroy the enemy forces in north-eastern Bulgaria and to occupy the Ruse-Varna area.

Hypothesis Z estimated that the opposing forces would have a maximum of 120.000 Bulgarian, German and Turkish soldiers and was based on the assumption that most of the Bulgarian forces would be tied down in the Thessaloniki area, before the Central Powers could call in reinforcements from other fronts or reserves.

Mackensen and the Bulgarians

The Central Powers knew that Romania could quickly become vulnerable to an attack from the south. German Field Marshall August von Mackensen, at the suggestion of Erich von Falkenhayn, drew up a plan to address the action taken by Romania. In the first phase, it envisioned an attack by Bulgarian and German forces against the Allied army, led by the French general Sarrail, on the Thessaloniki Front. In the second phase, the Bulgarian-German troops were to be quickly moved from the Thessaloniki Front to the border with Romania for a direct attack in the direction of Dobruja. The main target was Turtucaia, a victory there clearing the way for an attack on Dobruja.

The Entente knew of this vulnerability and had to prevent it with an attack by the Allied troops on the Thessaloniki Front. But the Bulgarian-German troops were the first to carry out the attack. When their onslaught was finally halted on August 15/28, the Bulgarian-German command decided to move some of its troops to the north against Romania.

The place chosen for the attack, Turtucaia, was located only 60 km from Bucharest and was a junction between Silistra and Rusciuc.

The victory at Turtucaia gave the Central Powers a breather. The news of Turtucaia’s conquest produced unusual enthusiasm among the German leaders. Kaiser Wilhelm, who at the entry of Romania into the war “lost his temper” and declared that “the war was lost for Germany”, recovered after the initial depression, celebrating with a champagne party in honour of the Bulgarian representative.

The attack of the German-Bulgarian troops in the south of Romania and their advance in the south of Dobruja overturned the plans of the Romanian army. Some of the troops that entered Transylvania were withdrawn to be used on the Danubian Front. During this time, many strong German and Austro-Hungarian divisions arrived in Transylvania.


Glenn E. Torrey, România în Primul Război Mondial [Romania in the First World War], Meteor Publishing House, Bucharest, 2014.

I.G. Duca, Memorii [Memoirs], vol. I, Expres Publishing House, Bucharest, 1992.

The Count of Saint-Aulaire, Însemnările unui diplomat de altădată: În România: 1916-1920 [The testimonies of a former diplomat: In Romania: 1916-1920], Humanitas Publishing House, Bucharest, 2016.

Constantin Argetoianu, Memorii [Memoirs], Humanitas, Bucharest, 1992.

Florin Constantiniu, O istorie sinceră a poporului român [A sincere history of the Romanian people], Encyclopaedic Universe Publishing House, Bucharest, 2008.

Translated by Laurențiu Dumitru Dologa