unsatisfactory and on July 28 declared war on Serbia. In the meantime the Russian ambassador in Vienna had stated that "any action taken by Austria to humiliate Serbia could not leave Russia indifferent." Austria's action in declaring war, then, is explicable on only two grounds either she was convinced that Russia was bluffing and would back down, or else Austria was prepared deliberately to bring on a general European war.

Germany and Russia. Throughout all these negotiations Germany had backed Austria fully, refusing to make any move which might have helped in preserving the peace. Now Russia began to mobilize her armies. It became plain that the only hope for peace was to secure some agreement between Russia and Austria. Many efforts. to this end were put forth, and on July 31 Austria finally agreed to discuss with Russia the terms of the ultimatum to Serbia. This slim chance of preventing a break at the eleventh hour was immediately nullified by an ultimatum delivered by Germany to Russia at midnight on July 31, demanding that Russia should cease military preparations and begin to demobilize her armies within twelve hours. Russia made no reply; and at 5 P. M. on August 1 Germany declared war on Russia. This action necessarily involved war also on France, for France could hardly refuse to aid her ally.

Germany and Belgium. In 1839 Great Britain, France, Austria, Russia, and Prussia joined in guaranteeing the independence and perpetual neutrality of Belgium. Treaties between Great Britain and France and between Great Britain and Prussia, signed just before the Franco-Prussian War of 1870, pledged Great Britain to aid in defending the neutrality of Belgium if either belligerent violated it. In July, 1914, when war again became imminent, Great Britain tried to secure a renewal of this agreement of 1870.

France expressed a willingness to make such an agreement; but the German Government refused to agree to respect the neutrality of Belgium, and two days later, on August 2, demanded the right of passage through Belgian territory. Belgium returned a flat refusal and was invaded on August 4. Later, the same day, Great Britain declared war on Germany. That the German authorities realized the seriousness of this step is evidenced by the efforts of Chancellor von Bethmann-Hollweg and of the Kaiser to condone what each frankly admitted was a breach of international law and a wrong, insisting, however, that military necessity demanded it. Von Bethmann-Hollweg added "Necessity knows no law."

PROGRESS OF THE WAR

The Invasion of France. The plan of campaign of the German general staff was for Austria together with a small number of German troops to hold the Russians in check while Germany crushed France, the two then uniting for a later campaign against Russia. Following this plan, the German armies, by a surprise thrust through Belgium in August, 1914, sought to paralyze the French armies. The German advance through Belgium was much slower than had been anticipated on account of the stiff fight put up by the little Belgian army. So it was August 24 before the frontier between France and Belgium was crossed. This delay gave the French time to rearrange their armies, and the surprise element was lost. General Joffre, who took command of the French armies on August 20, outmaneuvered the German field officers and, aided by the British, defeated the Germans in the great battle of the Marne, September 6-10, 1914. The Germans had nearly reached Paris, but now they retreated for some

miles and dug themselves in. Severe fighting raged throughout Flanders, but neither side was able to break through, and the conflict in the West settled down into the type of trench warfare which is the characteristic feature of this war. The battle of the Marne bids fair to be regarded as the decisive battle of the war. It was here that the plans of the German staff were definitely defeated. Paris was saved, and France was not crushed.

The War in the East. In the meantime on the Eastern front the Russian armies had mobilized much more rapidly than had been believed possible. As early as August 17 they invaded East Prussia and soon threatened the fortress of Königsberg. But a skillful maneuver by the German general, von Hindenburg, around the Mazurian Lakes and a German victory at Tannenberg nearly succeeded in crushing the Russian armies in East Prussia. Other Russian armies had invaded Austrian Galicia, taken Lemberg, and practically routed the Austrian armies sent to hold the frontier. Indeed, one of the contributing causes of the defeat of the Germans at the Marne was the necessity, at the critical moment, of sending eastward to stay the Russians several divisions from the armies opposing the French and British. The Eastern campaign of 1914 ended with Russia in possession of a considerable part of Austrian Galicia, and Germany in possession of a fair slice of Russian Poland.

During the winter of 1914-1915 the Russians pushed gradually forward into the passes of the Carpathians. In the spring of 1915 they launched a great drive which carried them over the mountains into Hungary and won them the great fortress of Przemysl in western Galicia (March, 1915). Then a failure in the supply of ammunition caused a sudden reversal, and the summer of 1915 saw the Russians retreating rapidly, while place after place - Warsaw,

Brest-Litovsk, Vilna, and many others- fell into the hands of the Germans and Austrians, led by von Hindenburg. By September, 1915, the Teutonic Allies held practically a straight line from Riga to the Rumanian frontier. Italy and the War. Italy, it will be remembered, was bound by the terms of the Triple Alliance to assist Germany and Austria-Hungary in case they should be attacked by other nations. Italy refused to aid her allies in August, 1914, on the ground that Germany and AustriaHungary were waging an aggressive instead of a defensive war. During the winter of 1914-1915 belligerent Italian patriots had warmly advocated their country's entrance into the war as an enemy of Austria-Hungary, hoping thus to win the territory still held by Austria and inhabited by Italians. Austria offered various concessions in an effort to secure peace, but on May 23, 1915, Italy declared war and undertook an invasion of Austria. This invasion, due to the mountainous character of the country and other handicaps, in over two years won very little territory for the Italians, and all of these gains were lost in the latter part of 1917.

Conquest of Serbia. After two Austro-Hungarian attempts to invade Serbia had failed in August and December, 1914, a new Austro-German invasion was undertaken in October, 1915, under the direction of the German general, von Mackensen. Belgrade was captured October 8, and a few days later, October 14, Bulgaria declared war and invaded Serbia from the southwest. The Serbian armies were thus caught between the two attacks and were speedily overcome. Aid which had been promised by Great Britain and France arrived too late. By the end of November the whole of Serbia had been conquered and overrun. The next two months saw the conquest of Montenegro.

Turkey and the War. After Turkey entered the war in October, 1914, the Russians and British undertook several invasions. The most spectacular of these was the attempt of the British in February, 1915, to force the Dardanelles and open the route to the Black Sea and South Russia. It was a brilliant conception, and its success would probably have eliminated Turkey from the war and made possible the shipment of munitions and other supplies to Russia by the Black Sea route. The attack was badly managed, however, and in spite of brilliant fighting by the Australian and New Zealand troops, ended in total failure. A Russian invasion of Turkish Armenia precipitated a general massacre of the Armenians by the Turks. The Russians gained some territory in this region. British invasions of the Euphrates valley and of Palestine, while they have gained some territory for the British, have thus far had no important effects on the war.

Rumania and the War. Rumania entered the war in August, 1916, believing the time was ripe to win the Transylvanian region which she had long coveted. The 3,000,000 Rumanians who form the largest part of the population of Transylvania have been systematically deprived of rights by their Magyar rulers, and Rumania desired to liberate them from this oppression. Some early successes for her armies carried her invasion of Austria-Hungary as far as Hermannstadt. It was freely predicted that the utter exhaustion of the Teutonic Allies was at hand. Soon, however, Rumania was attacked from the south by Bulgaria, and on the north by fresh German and Austrian armies. Her defense collapsed; the promised Russian aid did not arrive; and before the end of 1916 nearly the whole of Rumania was in the hands of her enemies. Early in 1918, after the collapse of Russia, she was forced to sign a very humiliating peace treaty.