The Georgian-Armenian War was a short border dispute fought in December 1918 between the newly-independent Democratic Republic of Georgia and the First Republic of Armenia, largely over the control of former districts of Tiflis Governorate, in Borchaly  and Akhalkalaki. In March 1918, Russia signed the Treaty of Brest-Litovsk and in doing so agreed to return to the Ottoman Empire territory gained during the 1877-78 Russo-Turkish War. These territories were, however, no longer under the functional control of the Russian central government; rather, they were being administered collectively by the Georgians, Armenians and Azerbaijanis through the Transcaucasian Sejm. The Trebizond Peace Conference aimed to resolve the dispute, but when the conference failed to produce a resolution, the Ottomans pursued a military campaign to control the disputed territories. Under persistent attack, the Transcaucasian collective eventually dissolved with the Georgians, Armenians and Azerbaijanis declaring independent nation states in quick succession in late-May 1918. On 4 June, the Ottoman Empire signed the Treaty of Batum with each of the three Transcaucasian states, which brought the conflict to an end and awarded the southern half of the ethnically-Armenian Lori Province and Akhalkalaki district to the Ottomans. Against the wishes of Armenia, Georgia, supported by German officers, took possession of northern Lori and established military outposts along the Dzoraget River. When the Ottomans signed the Armistice of Mudros in October, they were subsequently required to withdraw from the region. Armenia quickly took control of territory previously controlled by the Ottomans, and skirmishes between Armenia and Georgia arose starting on 18 October. Open warfare began in early December, after diplomatic efforts failed to resolve the issue of the disputed border, and continued until 31 December, when a British-brokered ceasefire was signed, leaving the disputed territory under joint Georgian and Armenian administration.. How many months did warfare continue after skirmishes arose between Armenia and Georgia?