Question: Siegfriedstellung in the First World War was a defensive position of what country's army?

Context:
Pomeranian Wall
The Pomeranian Wall, Pomeranian Line or Pomeranian Position (German: "Die Pommernstellung" , Polish: "Wał Pomorski" ) was a line of fortifications constructed by Nazi Germany in the Pomeranian Lakeland region.
 It was constructed in two phases.
 In the years 1930-1935 it was constructed as a light defensive position in case of an attack from the Second Polish Republic against the German republic.
 The line of fortifications stretched from Landsberg an der Warthe (Gorzów Wielkopolski) to Baldenburg (Biały Bór) and Pollnow (Polanów).
 The fortifications had several impressive strong points, particularly near Deutsch-Krone (Wałcz) and the 'Hangman Mountain'.
 The second phase took place during the Second World War, in 1944, when after a series of defeats on the Eastern Front the Pomeranian Wall was renovated in order to stop the Red Army advance.
 Various battles along the Pomeranian Wall took place particularly from January to March 1945, for example, the Battle of Kolberg, with the Red Army and units of the Polish People's Army eventually breaking through the wall in various places.
Dury Memorial
The Dury Memorial is a World War I Canadian war memorial that commemorates the actions of the Canadian Corps in the Second Battle of Arras, particularly their breakthrough at the Drocourt-Quéant Line switch of the Hindenburg Line just south of the town of Dury.
 The Drocourt-Quéant Line was a main position in the German Army's defensive position in the area.
 The action took place on 2 and 3 September 1918 during a period known as the Hundred Days Offensive or Canada's Hundred Days.
 Particularly noteworthy for such a brief battle was that seven Canadians earned a Victoria Cross on 2 September during the battle.
Defence of Festubert
The Defence of Festubert was an engagement early in the First World War when Indian and British battalions of the 7th (Meerut) Division, Indian Army defended the village of Festubert against a German attack from 23–24 November 1914.
 It is notable for being one of the first actions in the war in which an attack was made against a prepared defensive position, thus foreshadowing the years of trench warfare which were to come.
Leipzig Salient
The Leipzig Salient was a German defensive position built in 1915 on the Somme in France, during the First World War, opposite the village of Authuille which contained the Leipzig Redoubt on its west face.
 The position was to the south-west 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, which had been dug further back across the chord of the salient.
 The "Wundtwerk" Redoubt (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 north-west.
Hohenzollern Redoubt (1916)
The Hohenzollern Redoubt was a German defensive position on the Western Front during the First World War.
 The redoubt was north of Loos-en-Gohelle (Loos), a mining town north-west of Lens in France.
 The redoubt was fought over by the British and German armies from the Battle of Loos (25 September – 8 October 1915) to the beginning of the Battle of the Somme on 1 July 1916.
 Over the winter of 1915–1916, the 170th Tunnelling Company RE dug several galleries under the German lines in the Hohenzollern Redoubt area, which had changed hands several times since September 1915.
 In March 1916, the west side was held by the British and the east side was occupied by the Germans, with the front near a new German trench known as The Chord.
 The Germans had an unobstructed view of the British positions, from a slag heap called "Fosse" 8 and in previous mining operations, no man's land had become a crater field.
 The British front line was held by outposts to reduce the number of troops vulnerable to mine explosions and the strain of knowing that the ground could erupt at any moment.
Action of 22 August 1917
The Action of 22 August 1917, took place in the First World War, on the Western Front during the Third Battle of Ypres in the Ypres Salient, between the Fifth Army of the British Expeditionary Force and the German 4th Army.
 During the Battle of Langemarck (1917) (16–18 August), the British had advanced north of the village but had been defeated further south and failed to capture the "Wilhelmstellung" , the third German defensive position.
 At a conference with the Fifth Army corps commanders on 17 August, Gough arranged for local attacks to gain jumping-off positions for a general attack on 25 August.
 At the Action of the Cockcroft on 19 August, XVIII Corps assisted by the 1st Tank Brigade, had captured five German fortified farms and strongpoints for only 27–28 casualties.
Attacks on the Butte de Warlencourt
The Butte de Warlencourt is an ancient burial mound off the Albert–Bapaume road, north-east of Le Sars in the Somme "département" of northern France.
 It is located on the territory of the commune of Warlencourt-Eaucourt and slightly north of a minor road to Gueudecourt and Eaucourt l'Abbaye.
 During the First World War, the Germans constructed deep dugouts throughout the butte and surrounded it by several belts of barbed wire, making it a formidable defensive position in advance of "Gallwitz Riegel" (the Gird Trenches).
 After the Battle of Flers–Courcelette (15–22 September 1916), the view from the butte dominated the new British front line and was used by the Germans for artillery observation.
Battle of Verdun
The Battle of Verdun ("Bataille de Verdun", ] , "Schlacht um Verdun", ] ), fought from 21 February to 18 December 1916, was the largest and longest battle of the First World War on the Western Front between the German and French armies.
 The battle took place on the hills north of Verdun-sur-Meuse in north-east France.
 The German 5th Army attacked the defences of the Fortified Region of Verdun ("RFV, Région Fortifiée de Verdun") and those of the French Second Army on the right bank of the Meuse.
 Inspired by the experience of the Second Battle of Champagne in 1915, the Germans planned rapidly to capture the Meuse Heights, an excellent defensive position with good observation for the artillery to bombard Verdun.
 The Germans hoped that the French would commit their strategic reserve to recapture the position and suffer catastrophic losses in a battle of annihilation, not costly for the Germans because of their tactical advantage.
Siegfried Line
The original Siegfried Line (German: "Siegfriedstellung" ) was a First World War line of defensive forts and tank defences built by Germany in northern France during 1916–17 as a section of the Hindenburg Line.
 In English the term "Siegfried Line" commonly refers to the "Westwall", the German term for a similar Second World War-era defensive line built further east during the 1930s opposite the French Maginot Line.
 This line stretched more than 630 km and featured more than 18,000 bunkers, tunnels and tank traps.
 The network of defensive structures stretched from Kleve on the border with the Netherlands, along the western border of the old German Empire, to the town of Weil am Rhein on the border to Switzerland.
 It was planned in 1936 and built between 1938 and 1940.
Hindenburg Line
The Hindenburg Line ("Siegfriedstellung" or Siegfried Position) was a German defensive position of World War I, built during the winter of 1916–1917 on the Western Front, from Arras to Laffaux, near Soissons on the Aisne.
 In 1916, the German offensive at the Battle of Verdun had been a costly failure.
 The Anglo-French offensive at the Battle of the Somme had forced a defensive battle on the Germans, leaving the western armies ("Westheer") exhausted.
 On the Eastern Front, the Brusilov Offensive had inflicted huge losses on the Austro-Hungarian armies in Russia and forced the Germans to take over more of the front.
 The declaration of war by Romania had placed additional strain on the German army and war economy.
 Construction of the Hindenburg Line in France was begun by the Germans in September 1916, to make a retirement from the Somme front possible, to counter an anticipated increase in the power of Anglo-French attacks in 1917.

Answer: German