The Ovche Pole Offensive Operation was an operation of the Bulgarian Army that occurred between 14 October 1915 and 15 November 1915 as part of the Serbian campaign of 1915 in World War I. It aimed to seize the Vardar river valley and to cut the vital railway linking Skopje with Thessaloniki to prevent the Serbian Army from being resupplied and reinforced by the Franco-British Allied forces. Wikipedia