Second Balkan War

The Second Balkan War was a brief but intense conflict fought from June 29 to August 10, 1913.

It involved the Kingdom of Bulgaria fighting against its former allies in the Balkan League. These former allies included Serbia and Greece. Soon, Romania and the Ottoman Empire also joined the fighting against Bulgaria. This war was a direct result of disagreements over how to divide land gained during the First Balkan War. It fundamentally changed the political balance in the Balkan region of Europe.

The conflict began because of a breakdown in diplomacy and broken agreements.

In 1912, Bulgaria and Serbia signed a secret agreement to share northern Macedonia. They planned to use the Kriva Palanka–Ohrid line as a boundary. However, after the First Balkan War, Serbian forces occupied territory far south of this agreed line. Greece also moved north and occupied Thessaloniki.

Bulgaria felt these territorial gains were unfair and violated their previous pacts. This tension made a second war between these neighbors almost inevitable.

Bulgarian leadership made highly risky decisions to start the war.

Tsar Ferdinand I and the Bulgarian military high command wanted to secure more territory. They aimed to control all of Macedonia and parts of Thrace. On June 16, the high command ordered a surprise attack against Serbian and Greek positions. They did this without a formal declaration of war. This sudden offensive was intended to seize land before Great Powers could intervene. However, the plan did not account for other neighbors joining the fight.

The Bulgarian military strategy suffered from a major flaw in its planning.

To gain an advantage, Bulgaria committed nearly its entire army to the south. They focused all their strength on attacking Serbia and Greece. This left the northern border with Romania almost entirely undefended. Bulgaria also failed to prepare for a potential counterattack from the Ottoman Empire. They incorrectly assumed that Russia would protect their borders through arbitration. This lack of preparation meant Bulgaria was vulnerable on multiple fronts.

As the fighting progressed, Bulgaria faced pressure from several different directions.

Serbia and Greece successfully repelled the Bulgarian offensive. While the Bulgarian army was busy in the south, Romania intervened from the north. Romanian forces advanced toward Sofia, which is the capital of Bulgaria.

At the same time, the Ottoman Empire took the opportunity to recover territories. Bulgaria was now fighting a war on many sides at once. The military setbacks and the advance toward the capital forced Bulgaria to request an armistice.

The war concluded with the Treaty of Bucharest in August 1913.

This treaty forced Bulgaria to cede significant amounts of land. They had to give Southern Dobruja to Romania. Parts of Macedonia were handed over to Serbia and Greece. Additionally, the separate Treaty of Constantinople forced Bulgaria to give Adrianople to the Ottoman Empire.

These losses weakened Bulgaria and left the nation feeling deeply dissatisfied with the new borders.

The Second Balkan War had lasting consequences for European politics. Serbia grew much larger and more influential in the region. This expansion increased the rivalry between Serbia and Austria-Hungary. Bulgaria's defeat and loss of territory changed its foreign policy. Later, Bulgaria would align itself with the Central Powers during the First World War. The war also damaged the relationship between Bulgaria and Russia. Because Russia failed to protect Bulgaria's interests, the two nations ended their long-standing alliance.