I Weltkriege

Weltkriege, I (1914-18 War). The war, the causes of which are still to some extent a matter of controversy, was occasioned by the assassination of the Austrian Archduke Franz Ferdinand on 28 June 1914. Hostilities began with the declaration of war by Austria-Hungary on 28 July. War between Russia and Germany with Austria-Hungary began on 1 August, between Germany and France on 3 August, and, after the German invasion of Belgium, between Germany and Great Britain on 4 August. Italy declared its neutrality on 1 August. Late accessions to the central powers were Turkey, on 1 November 1914, and Bulgaria, on 14 October 1915. Italy joined the Allies on 23 May 1915.

The German plan (see Schlieffen-Plan) was concentration and quick victory by envelopment in the west, containment by small forces in the east with the support of the Austro-Hungarian army. In spite of great gains, the plan in the west failed, but the defending armies in the east won unexpected and important victories at Tannenberg and in Masuren. A stalemate in the form of trench warfare ensued in the west, which lasted for almost four years, interrupted from time to time by unsuccessful offensives, which entailed heavy losses of men and great expenditure of material (see Verdun, Schlacht um).

On the eastern front great gains were made against the Russians, but heavy losses seriously weakened the Austro-Hungarian armies. At sea the principal features were the British blockade and German submarine warfare, which began in February 1915 and was suspended in September 1915. Unrestricted submarine warfare, begun on 1 February 1917, led the USA to declare war on 6 April 1917. The Russian March and November Revolutions culminated in the virtual surrender of Russia in the Treaty of Brest-Litovsk (3 March 1918).

The German attempt to break the deadlock in the west by a series of massive attacks began on 21 March 1918 (März-Offensive). These achieved initial successes, but were all halted. In July 1918 the Allies, reinforced by the Americans, attacked, and continued to advance slowly until the end. The Turkish front collapsed in the autumn of 1918, the Bulgarians surrendered in September, and the Austro-Hungarian monarchy disintegrated in October. The German request for an armistice was made on 3 October, the German navy mutinied on 28 October, the Emperor Wilhelm II fled to Holland on 10 November, and the armistice came into effect on 11 November 1918. (See also Versailles, Treaty of.)