The Leipzig Salient was the British term for a German defensive position built in 1915 on the Somme front in France, during the First World War. The Salient was opposite the village of Authuille that contained the Leipzig Redoubt on its west face. The position was to the south-west of the site of the later Thiepval Memorial, north-east of the La Boisselle–Authuille and Thiepval–Aveluy crossroads. The German front line bulged around a quarry which the Germans fortified and enclosed with Hindenburg Trench across the chord of the salient. A redoubt named the Wundtwerk (Wonderwork to the British) lay beyond on a reverse slope. Nab Valley lay on the east side, Thiepval was to the north, with the fortified Mouquet Farm and the village of Pozières to the east.
On the First day on the Somme (1 July 1916), the Leipzig Salient was attacked by the 1/17th Highland Light Infantry (17th HLI) of the 32nd Division. The battalion crept forward at 7.23 a.m., ready to rush the German defences as soon as the British barrage lifted at 7:30 a.m. The Scots advanced until 30–40 yd (27–37 m) short of the German front line, rushed the redoubt when the barrage lifted and caught the German garrison sheltering in their quarry dugouts at the centre of the redoubt. The 17th HLI pressed on to the next objective but were forced back to the Leipzig Redoubt and consolidated with parties of the 2nd King's Own Yorkshire Light Infantry.
The 17th HLI was joined at the redoubt by parties of the 11th Border Regiment, 1st Dorset Regiment and the 19th Lancashire Fusiliers (3rd Salford Pals) during the day and the 17th HLI was withdrawn overnight. British and German attacks at the salient continued during July, when the Reserve Army divisions north of the Albert–Bapaume road reverted to trench warfare, in which the 32nd Division, 25th Division and the 49th (West Riding) Division (X Corps) occupied Leipzig Redoubt in turn during the rest of the month.
The divisions were to push forward to improve their positions and to prevent the Germans from withdrawing troops for operations against the Fourth Army to the south. Both sides made costly attacks but could rarely consolidate gains before being forced out by counter-attacks. Intermittent operations at the Leipzig Salient continued as part of the Battle of Pozières (23 July – 3 September) and the Battle of Thiepval Ridge (26–28 September), when the Thiepval Spur was captured by the 18th (Eastern) Division.
Background
1914
On 29 September the 26th Reserve Division attacked eastwards towards Albert and Thiepval on the north side of the Bapaume–Albert road with Reserve Infantry Brigade 51. Thiepval was occupied unopposed but French troops were found to have dug in at Thiepval Wood and German patrols were held up at the Ancre crossings which the French had blocked with barbed wire. An attack by a company of Infantry Regiment 180 on Authuille was brought to a standstill 0.62 mi (1 km) south-west of Thiepval. A French counter-attack from Hamel began in the evening and in the early hours of 30 September, two German companies were surrounded and had to break out to the east.
Somme fortifications
On the Somme front, the fortification plan ordered by Falkenhayn in January 1915 had been completed during the year. Barbed wire obstacles had been enlarged from one belt 5–10 yd (4.6–9.1 m) wide to two belts 30 yd (27 m) wide and about 15 yd (14 m) apart. Double and triple thickness wire was used and laid 3–5 ft (0.91–1.52 m) high. The front line had been increased from one trench line to three, 150–200 yd (140–180 m) apart, the first trench occupied by sentry groups, the second (Wohngraben) for the bulk of the front-trench garrison and the third trench for local reserves. The trenches were traversed and had sentry-posts in concrete recesses built into the parapet. Dugouts had been deepened from 6–9 ft (1.8–2.7 m) to 20–30 ft (6.1–9.1 m), 50 yd (46 m) apart and large enough for 25 men. An intermediate line of strong points (the Stützpunktlinie) about 1,000 yd (910 m) behind the front line was also built. Communication trenches ran back to the reserve position, renamed the second position, which was as well built and wired as the first position. The second position was beyond the range of Allied field artillery, to force an attacker to stop and move field artillery forward before an attack.
After the Herbstschlacht (Autumn Battles) of 1915, a third defensive position another 3,000 yd (1.7 mi; 2.7 km) back from the Stützpunktlinie was begun in February 1916 and was almost complete on the Somme front when the battle began. German artillery was organised in a series of Sperrfeuerstreifen (barrage sectors); each officer was expected to know the batteries covering his section of the front line and the batteries ready to engage fleeting targets. A telephone system with lines buried 6 ft (1.8 m) deep for 5 mi (8.0 km) behind the front line, was built to connect the front line to the artillery.
The Somme defences had two inherent weaknesses which the rebuilding had not remedied. The front trenches were on a forward slope, lined by white chalk from the subsoil and easily seen by ground observers. The defences were crowded towards the front trench, with a regiment having two battalions near the front-trench system and the reserve battalion divided between the Stützpunktlinie and the second position, all within 2,000 yd (1,800 m) and most troops within 1,000 yd (910 m) of the front line, accommodated in the new deep dugouts. The concentration of troops at the front line on a forward slope guaranteed that it would face the bulk of an artillery bombardment, directed by ground observers on clearly marked lines.
Granatloch (Leipzig Salient)
The German fortification programme led to the building of a redoubt south of Thiepval known as Granatloch (Leipzig Salient to the British), where the German line bulged westwards around a derelict chalk quarry. To the south-west lay the Ovillers–Authuille and Thiepval–Aveluy crossroads and more defensive works, Hindenburg Trench, Lemberg Trench and the Wundtwerk (named after Generalleutnant Theodor von Wundt, commander of Reserve Infantry Brigade 51) and known as the Wonderwork by the British, were dug behind the redoubt. Nab Valley lay to the east, Thiepval was to the north and to the north-east near Pozières lay the fortified Mouquet Farm. The salient blocked the route to Schwaben Redoubt at the top of Bazentin Ridge, from which the spurs leading south and south-west could be outflanked. The Wundtwerk was an irregularly shaped six-sided trench network higher up the spur which, with the other fortified places and villages, commanded the approaches to Granatloch.
Prelude
German preparations
The German front line opposite X Corps was held by eight battalions in the centre of the sector occupied by the 26th Reserve Division, mostly raised in the Kingdom of Württemberg and part of the XIV Reserve Corps (Generalleutnant Hermann von Stein). Opposite the 32nd Division the defences were held by I and II battalions, Reserve Infantry Regiment 99 of Reserve Infantry Brigade 55, each having three companies in the front line and one in reserve, with headquarters in Mouquet Farm to the east. At the south end of the 26th Reserve Division area, Thiepval south was held by Infantry Regiment 180, which had been moved south from Serre in June. The German defences ran along the northern slope of the Ovillers Spur, bent eastwards into Nab Valley then westwards to enclose the west end of Thiepval Spur and the western fringe of Bazentin Ridge, then north to St Pierre Divion on the Ancre river. On most of the front, the German defences were on higher ground but convex slopes meant that much of the Ancre valley to the west was in dead ground. Authuille and Thiepval woods on the east bank of the Ancre and Aveluy Wood on the west side, covered much of the ground behind the British front line, in which assembly positions could be built unseen and then occupied by British troops, as they massed for the attack.
The village of Thiepval was opposite the centre of the X Corps sector, on a spur within the German front position, at the junction with Bazentin Ridge. During the British preparatory bombardment, most of the sixty dwellings in the village were demolished but the house cellars were covered by fallen masonry, which protected them from all but super-heavy shells. None of the German machine-gun positions was hit and shelters excavated under the village, provided accommodation for the garrison during the bombardment and protected ammunition stores and machine-guns, ready to be moved into the open. A chain of cellars, on the west fringe of the village, had been joined to form a connected line of machine-gun posts, which had been kept silent to surprise an attacker. The château ruins in the south-west corner had also been fortified. Both sets of machine-guns could sweep all the upper western slope of Thiepval Spur and enfilade an attack further south as far as Authuille. South of Thiepval, lay the Leipzig Redoubt, at the west end of the Leipzig Salient, containing many machine-guns, which dominated no man's land, from 200–600 yd (180–550 m) wide to the west and the south, the narrowest point being opposite Leipzig Redoubt.
In the German third or reserve trench, four fortified works had been built, the Wundtwerk (Wonderwork) on the reverse slope to the south of the Leipzig Redoubt, out of sight of British ground observers and placed to stop an advance over the spur, if the front trenches were overrun. A second redoubt was built at the back of Thiepval and Schwaben Redoubt atop the Bazentin Ridge, commanding the village and ridge below. Further north the fortified village of St Pierre Divion anchored the first position on the Ancre. An attack on the Leipzig Salient could be engaged by machine-guns in the Nordwerk on Ovillers Spur across Nab Valley, opposite the Nab. On the northern flank, Feste Alt Württemberg (Beaucourt Redoubt) covered the north and north-west slopes of Bazentin Ridge. A second position had been dug from Mouquet Farm to Grandcourt, protected by an intermediate line, from which the Mouquet Switch and the Hansa linie connected to Schwaben Redoubt. Behind the second position, another 3 mi (4.8 km) back, lay the third position, construction of which had begun after the Franco-British offensives of September 1915, which had shown that two defensive positions were no longer sufficient.
British preparations
The 49th (West Riding) Division, in corps reserve, was to transfer to the command of Lieutenant-General Hubert Gough, commander of the Reserve Army as soon as the assault divisions had taken their objectives, having moved forward before dawn to Aveluy Wood, ready to cross the Ancre. Bridges and causeways had been built for the occasion, shellfire having damaged the banks of the Ancre, which when canalised, had been raised above the old course of the river and had since reverted to marsh. X Corps had two heavy artillery groups and two counter-battery groups under the same commander with two 15-inch, two 12-inch, twelve 9.2-inch, twelve 8-inch and twenty 6-inch howitzers; twenty-eight 60-pounder and four 4.7-inch guns. The field artillery had a hundred and twenty-eight 18-pounder guns, thirty-six 4.5-inch howitzers and a groupe of twelve French 75 mm field guns from the 20th Artillery Regiment. The artillery had been well dug in and covered with steel joists and 3–4 ft (0.91–1.22 m) of soil; there was a heavy gun for each 57 yd (52 m) and a field gun for each 28 yd (26 m) of front.
The bombardment plan had six lifts for the heavy artillery, in which the super-heavy 15-inch and 12-inch howitzers were to lift seven minutes early. A creeping barrage had not been planned but the 18-pounders were to "search" from trench to trench in ten lifts, the 4.5-inch howitzers were to bombard strong points and move back at the same time as the field guns, the bombardment lifting from the German front trench at zero hour, to the reserve line from the Wonderwork to Schwaben Redoubt and St Pierre Divion. No discretion was allowed to subordinate commanders over the bombardment but two 9.2-inch howitzers were kept separate from the barrage, to bombard machine-gun nests about Thiepval. The spur from Auchonvillers to Mesnil and Aveluy Wood, gave good observation to the British and many posts were built along it, particularly a length called Brock's Benefit. The northern part of the corps front had a better view over German positions than the south, which was blocked by Aveluy Wood and it was believed that more damage had been done opposite the 36th (Ulster) Division, the wire being cut well north of Thiepval and reasonably well at the Leipzig Redoubt. Assembly trenches were dug just before the attack, which tired out many of the troops due to attack.
British plan
The X Corps area ran north for 2,500 yd (1.4 mi; 2.3 km), from the III Corps boundary at Authuille Wood in the middle of Nab Valley, along the lower slope of the Thiepval Spur east of the Ancre river to Hamel, where the line crossed to the west bank and over Auchonvillers Spur for another 1,000 yd (910 m), to the boundary with VIII Corps. The corps plan was to capture the Thiepval Spur in one attack, which would obtain positions from which the German front would be overlooked as far as Serre north of the Ancre and Pozières and Contalmaison to the south. Both divisions practised on trenches built to resemble the German defences, in which the 32nd Division was to attack on the right of the corps area, from the Leipzig Salient to Thiepval village. Just before the last bombardment began at 7:00 a.m., a cloud gas attack was to begin from cylinders put in no man's land the night before. The division was to assemble low on the Thiepval Spur from Authuille to Thiepval woods, with a section of a field company attached to each brigade. The 97th Brigade and 96th Brigade were to attack the west face of the spur from the Leipzig Salient to Thiepval and then advance across Nab Valley. The southern face of Leipzig Salient was not to be attacked, since it was anticipated that it would be outflanked by the advance to the north.