The Battle of Transylvania was the first major operation of the Romanian forces Campaign during World War I, beginning on 27 August 1916. It started as an attempt by the Romanian Army to seize the disputed province of Transylvania, and potentially knock Austria-Hungary out of the war. Although initially successful, the offensive was brought to a halt after Bulgaria's attack on Dobruja. Coupled with a successful German and Austro-Hungarian counterattack after September 18, the Romanian Army was eventually forced to retreat back to the Carpathians by late October.