The Greek-Serbian Treaty of Alliance is signed, paving the way for the Second Balkan War.
The Greek–Serbian Alliance of 1913 was signed at Thessaloniki on 1 June 1913, in the aftermath of the First Balkan War, when both countries wanted to preserve their gains in Macedonia from Bulgarian expansionism. The treaty formed the cornerstone of Greek–Serbian relations for a decade, remaining in force through World War I until 1924.