World War I: Allied troops break through the Bulgarian defenses on the Macedonian Front.
The Battle of Dobro Pole (Serbian: Битка код Доброг Поља, romanized: Bitka kod Dobrog Polja; Greek: Μάχη του Ντόμπρο Πόλε, romanized: Máchi tou Dóbro Póle), also known as the Breakthrough at Dobro Pole (Bulgarian: Пробив при Добро Поле, romanized: Probiv pri Dobro Pole), was a World War I battle fought between 15 and 18 September 1918. The battle was fought in the initial stage of the Vardar Offensive, in the Balkans Theatre. On 15 September, a combined force of Serbian, French and Greek troops attacked the Bulgarian-held trenches in Dobro Pole ("Good Field"), at the time part of the Kingdom of Serbia (present day Greece and North Macedonia). The offensive and the preceding artillery preparation had devastating effects on Bulgarian morale, eventually leading to mass desertions.
Despite being outnumbered and poorly equipped, certain Bulgarian units offered fierce resistance, delaying the Entente advance in Zborsko. However, the collapse of the front line enabled the Allies to assault Bulgarian positions from multiple directions and eventually quell the last pockets of resistance. The Central Powers' defeat at the Dobro Pole played a role in the Bulgarian withdrawal from the war and opened the way for the subsequent capture of Vardar Macedonia.