In 1878, under the pretext of the Russian-Turkish war, a revolt broke out in Epirus that led to a rise in guerilla warfare.
The 1877-1878 Russian-Turkish war represented one of the most serious crises of the Eastern War and ended with the defeat of the Ottoman Empire. The victor, Russia, demanded the creation of Greater Bulgaria as part of the Treaty of San Stefano. However, thanks to the intervention of Britain and Austria-Hungary, the treaty was modified at the Congress of Berlin. Romania, Serbia and Montenegro were recognised as independent states. During the war, the Greeks in Epirus, Thessaly, Macedonia and Crete revolted, though unsuccessfully. However, the negotiations at the Congress of Berlin resulted in Greece being granted Thessaly and the area of Arta in 1881.