First Battle of Cobadin
Part of the Dobruja Campaign of the Romanian Campaign of World War I
The Romanian river monitors at Rasova, oil on canvas by Dimitrie Știubei [ro]
Date 17–19 September 1916 Location Rasova, Cobadin, Tuzla; Romania Result Entente victory
Belligerents
Bulgaria  German Empire  Ottoman Empire	Romania  Russian Empire
Commanders and leaders
Stefan Toshev August von Mackensen Mustafa Hilmi Pasha	Alexandru Averescu Andrei Zayonchkovski
Strength
55 battalions and 24 squadrons 4 battalions and 3 squadrons 3 battalions(initially) Total: 62 battalions and 27 squadrons[1]	Total: 70+ battalions and 41 squadrons[1] 4 river monitors
Casualties and losses
Bulgaria 704 killed, 4,778 wounded, 611 missing  German Empire unknown  Ottoman Empire 36 killed, 348 wounded 62 missing Total: Over 740 killed, 5,126 wounded, 673 missing[2]	unknown

The First Battle of Cobadin, also known as the First Battle of the Rasova–Cobadin–Tuzla Line, was fought from 17 to 19 of September 1916 between the Bulgarian Third Army and the Romanian–Russian Army of the Dobruja. The battle ended in Entente tactical victory and forced the Central Powers to hold their offensive and assume a defensive stance till the middle of October.

The right flank of the Allied forces was supported by the Romanian Navy's Danube Flotilla, consisting mainly of four Brătianu-class river monitors. These warships blocked with mines the river sectors of Silistra, Ostrov, and Gura Borcea, protected the 8 September evacuation of Silistra, attacked enemy land convoys, and destroyed enemy batteries.^[3]