The German attack on Vimy Ridge (/Operation Schleswig-Holstein) was a local attack on the Western Front on 21 May 1916, during the First World War. The Germans intended to prevent mines being blown under German positions by capturing the British front line and mine gallery entrances. After the Third Battle of Artois (25 September – 4 November 1915) the French Tenth Army had held positions on the western slope of Vimy Ridge and the German 6th Army occupied positions on the steeper eastern slope. During the Battle of Verdun (21 February – 18 December 1916), the Tenth Army was withdrawn and the British First Army and Third Army, on either flank, took over the French positions.

The mine warfare waged by the French was continued by the British, exploiting the advantage of being on the dip slope and only having to dig horizontally into the ridge to undermine German positions. The Germans, on the steeper scarp slope, had to dig down before they could dig horizontally, a disadvantage made worse by a shortage of manpower and mining equipment. An attack was planned by the Germans to capture the British positions, from which mine galleries were being dug under the German defences. Success would gain more defensive depth and forestall mine attacks on the German positions before the British could organise their defences on the ridge.

The Germans attacked on 21 May and were able to consolidate their objectives before the British could conduct counter-attacks powerful enough to recapture the ground. In the attack and its aftermath the Germans suffered against A British plan to recapture the front positions and take the German side of the ridge was cancelled because of the demand for men and equipment for the forthcoming Battle of the Somme. The Attack on the Gommecourt Salient took priority over another attack on the ridge. British planning continued and became the basis for the much larger attack by the Canadian Corps at the Battle of Vimy Ridge (9–12 April 1917).

Background

Winter 1915–1916

Vimy Ridge extends from the Scarpe river valley east of Arras northwards for to the valley of the Souchez river. During the winter of 1915–1916, the German and French troops on the ridge spent much time trying to drain and repair trenches. In the area of the German 17th Reserve Division, long trenches were dug to divert water from the front trenches; in January 1916, about of duckboards were laid by Reserve Infantry Regiment 76 alone. Conditions were so bad in the front line that soldiers fraternised to alleviate the conditions; on 25 January, the German companies in the line were transferred to end the fraternising. Conditions became so bad that infantry units were set to work to maintain the troops in the front line. The rains and French mortar fire destroyed German field fortifications almost as fast as they were built. To gain more defensive depth and to mislead the French about German offensive preparations at Verdun, the I Bavarian Reserve Corps ( Karl von Fasbender) conducted (Operation Rupprecht), several carefully prepared local attacks.

A battalion of Reserve Infantry Regiment 229 built fake encampments and made several approach marches to simulate reinforcements to French reconnaissance aircraft. I began on 23 January, when the 2nd Bavarian Division blew mines and captured several French trenches near Thélus. The 50th Reserve Division conducted II on 24 January and III on 26 January. French mortar fire began at on 27 January and at French infantry made grenade attacks against Reserve Infantry Regiment 230 of the 50th Reserve Division, which managed to repulse the attacks. At the French bombardment reached the intensity of drumfire (shells exploding in such quick succession that the reports merged into a rumble) and at the Germans were forced to retire. To the north, the 1st Bavarian Division undertook IV on 28 January, against the French 390th and 97th Infantry Regiments of the , to improve the Bavarian positions on Hill 145. The plan was to sap forward until the front line was from the French lines and then attack after a bombardment and a mine explosion on each flank. The preparations were obvious and the French replied with small-arms fire and artillery bombardments.

Tenth Army

The relief of the French Tenth Army by the British First Army (General Charles Monro) and Third Army (Lieutenant-General Edmund Allenby) was accomplished by early March 1916. The French had held about of front running from Ransart in the south, east of Arras, west of Vimy, east of Souchez, west of Lens and east of Loos to the north. The southern portion of the line up to Arras had been quiet since the battles of manoeuvre in September 1914 and an informal truce had developed. Further north, in the area of the three great battles of Artois in 1914 and 1915, hostilities had continued and on 8 February, the Germans captured of trench south of Central Avenue (Ave). On 21 February, the first day of the Battle of Verdun, Reserve Infantry Regiment 162 of the |17th Reserve Division captured Hill 120 (Giessler Heights, called The Pimple or Hill 145 by the British) the only ridge-top position still held by the French from the offensives of 1915. The German positions on the ridge gave excellent observation over the positions inherited by the British and made finding artillery emplacements most difficult. The maze of derelict and active trenches and artillery positions on and behind the ridge turned out to be an advantage, because the German artillery lacked the ammunition to bombard every position; many empty ones were hit and then repaired as a deception.

Vimy Ridge

The vacated French defences on the ridge were considered by the British to be very poor, the French having relied on the firepower of their quick firing Canon de 75 modèle 1897 field guns, rather than continuous trench lines. In places, the British found that the front was only a line of sandbags on the earth. The ground was a quagmire and the front trenches could only be reached at night, after labouring through deep mud. By May the ground had dried, except in Zouave Valley. There were few communication trenches to the front line, they were waterlogged and filthy with corpses.

Where barbed wire had been put out, it was poor and in bad condition; the French positions were good enough for jumping-off lines for another attack but not for defence. The British resumed hostilities, only to find that their trench parapets were not bulletproof and both sides came into the open to dig better defences under a tacit truce. The British then found that the superiority of German observation was such, that turning the area into a "windy corner" of the Western Front had backfired; the construction of better defences was much harder than expected.

British army, corps and divisional boundaries were changed in early 1916, when divisions from the First Army, Second Army and Third Army were withdrawn to reinforce the Fourth Army on the Somme. On Vimy Ridge, the Berthonval and Carency sectors were transferred to IV Corps (Lieutenant-General Henry Wilson) of the First Army, from XVII Corps (Lieutenant-General Sir Julian Byng) of the Third Army and from the 25th Division to the 47th (1/2nd London) Division, which extended its right flank southwards to P sector. The positions were high along the western slope of Vimy Ridge and down the north-facing slope between Souchez and Givenchy-en-Gohelle. From south to north the communication trenches to the British front line on the ridge were Grange Ave and Lassalle Ave–Royal Ave in P sector. In the Berthonval sector, access was by Central Ave–Cannon Street, Wortley Ave–International Ave, Landwehr Ave and in the Carency sector, the communication trenches were Ersatz Ave–Ersatz Alley, Uhlan and Coburg alleys.

Neither side controlled the crest and to the south of the Berthonval sector, the British intended to treat the front line as the main line of resistance, to protect Zouave Valley, which rose southwards from the valley of the Souchez river, about back from the front line. German gunners continually bombarded the (Zouave embankment) in Zouave Valley, which could cut off British contact with the front line. The British could see the Douai Plain behind Vimy Ridge from Loretto Ridge to the north-west but the pit villages dotted around the Lens coalfield made plenty of hides for the German artillery.

IV Corps had the 23rd Division and 47th (1/2nd London) Division in the line and the 2nd Division (Major-General William Walker) in reserve near Brouay behind the front line. When the 47th (1/2nd London) Division moved its right flank to the south, the army boundary was shifted from Ersatz Ave to Central Ave. Two battalions of its 142nd Brigade held the Carency sector and a battalion of the 140th Brigade held the line in the Souchez sector, with the other battalions holding the Loretto Spur defences. During the reshuffle of 19/20 May, the northern defences were taken over by the 23rd Division and the 140th Brigade took over Berthonval from the 74th Brigade, 25th Division and the 141st Brigade took over Carency from the 142nd Brigade, which went into divisional reserve and the 7th Brigade, 25th Division in P sector came temporarily under the command of the 47th (1/2nd London) Division. The intention to use the French front line as the principal defence had been thwarted by the German miners and detached posts established instead of a trench line were under constant German observation. Troops moved forward after dark and held the posts from but hardly any more wire had been put out and the posts had no dugouts. The support line towards the bottom of the slope was supposed to be the main line of resistance but wet weather and German bombardments destroyed during the day what had been built in the night.

Prelude

British operations

When Haig discovered the real state of the French defences on the ridge, he ordered Allenby to hold the front line with outposts and strongpoints further back on the best defensive line that could be found. A retirement for , to a defensible line between Ecurie and Souchez, was judged politically impossible, after the great sacrifices made by the French in 1915. A retirement would also show the Germans that no spring offensive was intended, contrary to Haig's desire that one should be made to appear imminent by mining and trench raiding on the ridge. The British inherited a substantial French mining effort but found that German mining was more advanced. The war underground was taken over by the 172nd, 175th, 176th, 181st, 182nd, 184th, 255th Tunnelling Companies RE, the 23rd Division mining company and the New Zealand Tunnelling Company, with five French tunnelling companies (gradually reduced to two). For the infantry of both sides, the feeling of sitting on a volcano was nerve racking. When either side sprung a mine, their troops would rush forwards and try to consolidate the near lip as their opponents smothered the area with artillery and machine-gun fire.