It was followed on 20th Nov. by a British attack of an altogether different kind, in an unexpected quarter—at Cambrai. Here the Third Army, under General Byng, made an attack on a 10-mile front between St. Quentin and the River Scarpe—tanks being employed for the first time in large numbers to lead the advance without a preliminary bombardment. It was a complete surprise, and all but a complete success. The 'Hindenburg Line' was broken, numerous villages and 8000 prisoners were taken. If the cavalry had been up, as they ought to have been, a first-class disaster might have been inflicted on the Germans, and their railway communications at this point broken. But the cavalry were late; the next few days were spent in consolidation by peculiarly hard fighting; and on 30th Nov. the Germans counter-attacked and subjected the British defences of the newly-created salient at Bourlon Wood and Moeuvres to almost as severe a surprise as they had sustained ten days before. The British lost a number of prisoners, and had eventually to evacuate most of their hard-won positions.

French Front in the West, 1917

The history of the French armies in 1917 is largely the history of Nivelle's frustrated attempt to pierce the German centre between Soissons and Rheims in April; the pause necessitated by the fact that it was felt impossible to press the French armies too hard or too soon after the disappointment of the attenuated success at the Chemin-des-Dames, where the chief sacrifices of the attack took place; and the efforts on a more moderate scale by General Pétain, who succeeded Nivelle, to win tactical victories at a moderate cost on the terrain acquired in the April adventure. The second battle of the Aisne, as Nivelle's offensive was called, was planned over a length of 50 miles from La Fère, on the Oise, round the edges of the Forest of Gobain and Coucy, to Laffaux, thence below the line of the Chemin-des-Dames ridge and behind the Aisne to the crossing of the river at Berry-au-Bac, and Brimont, near Nogent-l'Abbesse, to the Moronvilliers heights on the other side of Rheims.

The attack on the larger part of this line began

on 16th April; that on the Moronvilliers sector on 17th April. The attack on the 16th was extremely costly; it succeeded in only part of its objectives, but it captured 11,000 prisoners. The next day, one of pouring rain, improved on the positions won, especially at the western end of the Chemin-des-Dames, and on the 18th and 19th Nivelle so far enlarged his successes as almost to give them the appearance of a great victory. But the French bolt had been shot, and, to put it plainly, Nivelle was not encouraged to go on. By the 28th he had taken 28,000 prisoners, 175 guns, and some of the strongest points on the heights of the Aisne; but everywhere the positions had been only half-won, and the temper of the French army as a whole had suffered too severe a test. Nivelle was succeeded by Pétain and his plan was abandoned. The rest of the year was occupied by General Pétain in very skilled attempts, named limited offensives, to repel the Germans from disputing some of the positions won and to enlarge the French gains at other points. The chief engagements were as follows:

5th May.—The French, co-operating with the British on a 20-mile front north of the Aisne, take Craonne and 6000 prisoners.

20th Aug.—French carry enemy defences north of Verdun on 11-mile front; 6000 prisoners. By 28th Aug. the French were back at their original Verdun positions.

23rd Oct.—French advance on the Aisne north-east of Soissons on e-mile front; 8000 prisoners. By 25th Oct. further 3000 prisoners and 160 guns were taken.

The Balkans, 1917

In the Balkans the military situation during 1917 remained much as the end of 1916 had left it, the Germans, as already mentioned, completing their conquest of Roumania, and the Allies remaining comparatively inactive in the field while they cleared up the extremely unsatisfactory situation in Greece. The chief operations consisted of a Franco-Serbian attack north of Monastir, and attacks by General Milne on the British front in the Struma valley; but though the situation remained in the field virtually unchanged, the political situation was vitally affected in 1917 by the deposition of King Constantine in favour of his second son, Alexander—the king being induced to abdicate on 12th June—and the formation of a new Government under M. Venizelos. From 30th June, Greece, having formally severed diplomatic relations with Germany, was at length added to the list of countries fighting on the Allies' side.

Italian Campaign, 1917

Italy, who, meantime, had proclaimed Albania an independent state under Italian protection, and occupied Yanina in June, 1917, had committed herself wholly to the Allies' cause in 1916 by declaring war on Germany on 28th Aug. It was in Aug., 1917 that Ludendorff began his preparations for the terrific blow which was to lead to the Italian disaster at Caporetto in October. During the earlier months of the year the initiative had remained with the Italians, and Cadorna had used it in a series of offensives which, while carrying him farther across the Carso towards Trieste, and winning seemingly impregnable positions in the Trentino, together with upwards of 30,000 prisoners and 140 guns, were indecisive, and left his exhausted troops—reduced by some 150,000 casualties—ripe for the blow which Ludendorff had prepared for them. The Russian Revolution and the collapse of Roumania freed Austria-Hungary at the same time from any anxieties on her Galicia front, so that she could concentrate all her energies and the bulk of her armies against the Italians. When the enemy's great counter-stroke was delivered on 24th Oct., the control of the campaign was taken over by the German High Command. Ludendorff had been training picked troops in special tactics—to be developed at their full strength on the Western front in the following year—and von Below was transferred from the French front to take command. Following an intense bombardment, the Austro-German troops were launched against the Second Italian Army between Zaga and Auzza, in deep formations so closely packed that the way could not be lost amid the prevailing snow and rain. Taken by surprise, and seriously demoralized in parts by Bolshevist propaganda and enemy intrigue, the Second Italian Army, which had hitherto distinguished itself by its splendid courage, found the whole of its left wing giving way before the impact, thus opening a gap for the enemy 20 miles wide over the Julian and Carnic Passes. Having shattered both the first and second Italian lines at Caporetto and Vodil Vrh, the Germans and Austrians surged forward from the Tolmino bridge-head until the retreating Italians, becoming entangled with their own reserves, broke in disorder. Although the right wing of the Second Army held, and many heroic efforts were made by isolated units, General Cadorna decided that it was impossible to save the situation from irretrievable disaster except by a general retreat to the Piave line. This was ordered on 26th Oct., when the broken fragments of the Second Army, as well as the Italian Third Army, began the great retreat which will be remembered as one