The Battle of Dobro Pole, also known as the Breakthrough at Dobro Pole in Bulgarian (Bulgarian: Пробив при Добро Поле, Probiv Pri Dobro Pole), (Serbian: Битка код Доброг Поља, Bitka Kod Dobrog Polja), (Greek: Μάχη του Ντόμπρο Πόλε, Máchi tou Dómbro Póle), 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 September 15, 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 Republic of Macedonia). The offensive and the preceding artillery preparation had devastating effects on Bulgarian morale, eventually leading to mass desertions.