Bulgaria declared war on Romania in 1916

On September 1, 1916, during World War I, Bulgaria declared war on Romania with the objective of reclaiming the Dobruja region and other ancestral territories.

To execute this campaign, Bulgaria deployed the 3rd Bulgarian Army, which included the 4th Preslav Infantry Division, the 1st Brigade of the 1st Sofia Division, and the Danube Bulgarian-German Detachment. Under the command of Major General Panteley Kiselev, the force consisted of approximately 55,000 soldiers, 132 guns, and 53 machine guns.

Key military actions included the cavalry operations led by General Ivan Kolev. His units protected the flanks during the assault on Tutrakan, prevented Romanian reinforcements from arriving, and participated in the liberation of Dobruja. Despite the historical ties between Bulgaria and the Russian Empire, which had liberated Bulgaria from Ottoman rule decades earlier, Bulgarian forces engaged against Romanian allies that included the Russian Empire and Serb-Croat volunteers.