After the signing of the London Peace Treaty on May 17, 1913, relations in the victorious coalition became strained.
The treaty ended the war, but did not eliminate the military situation in the Balkans. The reason was the tension that arose between the main players in the victorious coalition.
If a year ago Bulgaria managed to create an effective and successful bloc against the Ottoman Empire through diplomacy, in the months surrounding the preparation of the peace treaty in London Sofia fell into international isolation.
According to some historians, blinded by military successes, Tsar Ferdinand ordered our army to attack the recent allies Greece and Serbia on June 16, 1913.
He was impatient to wait for the arbitration of the Russian Tsar. The consequences were deplorable for Bulgaria. On June 27, 1913, Romania declared war on Bulgaria and, with almost no resistance, reached Vratsa. At Belogradchik, it met the Serbian army. Vidin fell into encirclement. The reason was that the main Bulgarian forces were thrown against the Greeks and Serbs.
On July 28, the Bucharest Peace Treaty of 1913 was signed, according to which Bulgaria was not only deprived to a significant extent of the lands liberated by it during the Balkan War of 1912-1913, but also suffered heavy financial and other losses.