but at a cost of 600,000 casualties. This overextension of lines caused the Allies to launch a counteroffensive the Germans were collapsing from all fronts and on November 11, 1918 the Germans surrendered to the Allies. Eastern Front The fighting on the Eastern Front was primarily contested by the German army and the Austria-Hungarian army on one side and the forces of the Russian Empire and Romania on the other. The Eastern front covered a very large territory, from the Baltic in the north to the Black Sea in the south and from Prussia and Galicia in the west to Latvia and Minsk to the east. The fighting on this front ended early, with the last significant military operation taking place in the autumn of 1917. The two Russian Revolutions of 1917 forced Russia out of the war. The Bolshevik government that took power in November 1917 had promised an end to the war and that government signed the Treaty of Brest-Litovsk which ended the war for Russia in March 1918. Italian Front The Italian Front covered only a small part of northern Italy and the western border of Austria-Hungary. The fighting here began on 23 May 1915 and lasted till 3 November 1918. Most of the fighting was concentrated on a very small bit of land between the Alps and the Adriatic, near the town of Trieste. The fighting primarily involved Italy and Austria-Hungary but also included smaller contingents from France, the UK, and the US (who fought on the side of Italy), and Germany (who was allied with Austria-Hungary). Balkans Front The Balkans Front covered all of Serbia, Montenegro, Albania, and Romania. It also covered northern Greece, the western part of Bulgaria, and the south and eastern parts of Austria-Hungary. Very little fighting took place in this theatre for long periods of time. It was considered a lesser theatre of war by the Great Powers. The Central Powers of Austria-Hungary, Germany, Bulgaria, and the Ottoman Empire were opposed by the allied powers of Serbia, France, the United Kingdom, Romania, Russia, Montenegro, and Greece. Naval conflict Because of the dominance of the British and French navies, only limited fighting took place in the seas around Europe. The German U-boat fleet tried to sink British merchant ships, with some success early in the war. German U-boats had only moderate cruising range in this war and operated mostly in the North