The fortified blocks of Guentrange, -die Feste Obergentringen-, situated 4 km to the north-east of Thionville occupy the summit of a strong hill wich lies in a south-westerly - north-easterly direction. It thus forms an initial buttress to the Moselle hills, wich from a height of 318 metres, dominate the wide valley of the Thionville region of the Moselle.
The Germans undertook these constructions in April 1899 and the defence works were known to be operational at the end of 1905. After the annexation of Alsace and part of Lorraine in 1871, the Germans intended to reinforce their new conquest over France. The Fort of Guentrange thus became part of this plan of fortifications of the Moselle between Metz and the Luxembourg frontier ( Moselstellung 1871-1914 ). By prolonging the enormous fortified works of Metz, and supported by the defence works of Illange and Koenigsmacker, the intention was to protect Thionville and its large railway network against any French attack. This mission was part of the Schlieffen-Moltke plan which foresaw that in the event of a Franco-German war, 5/7ths of the German army would invade France by passing through Belgium and Luxembourg, and that any offensive of the powerful right wing of the French army would be at the same time destined to fail, by coming up against the defence works of Metz and Thionville.
Although the Fort of Guentrange did not come under attack during the First World War it did play an important strategic role. It became French after the Armistice of 1918 and was integrated in the Maginot Line in the 1930ies. In 1940, the Germans recuperated the Fort and used it as a depot and workshop without maintaining troops there. The American army took it over in 1944 and destroyed some guns. After the war, the 25th Artillery Regiment, stationed in Thionville used the Fort as a munitions store.
Since 1971, the works have had no military vocation. Thanks to the efforts of the Town Council of Thionville and to the Friends of The Fortifications of Guentrange, it has become a remarkable stopping-off place for military tourism in Lorraine.


The organisation of the "Festen" differs completely from the diagrams used until then in France as well as in Germany. Rejecting the geometrical plan of the compact fort of 1874 enclosed in a polygon-shaped ditch, as it was conceived by the Séré de Rivière system, the "Feste" is a kind of unintelligible group composed of armoured gun turrets, of concrete barracks, and shelters widely spread out over the area, linked by subterranean galleries. A network of barbed wire and ditches enveloped the whole area. These defence works spread out over many acres, hardly visible to an observer on foot, as they were well-integrated in the landscape. The "Feste" had at its command a garrison of 2000 or more men, shielded guns in firing position - as many as twelve altogether, and it could sit out a siege of three months.


The initial plan of the Fort (1899-1905) was composed of three barracks; a central one which was the biggest, and two secondary barracks north and south of it. Between these buildings, higher up, two armoured guns each equipped with four non-retractable turning gun turrets, (the Schuman system) armed by a short canon of 105 mm (10 cm T.K.) with a range of 9700 metres could be found. In addition, each gun possessed powerfully protected look-out posts. The barracks, partially buried inside the hill, are of concrete (3 m for the floor surface and 3 to 4 metres thick for the back walls exposed to attack). Only the facades at the back, those turned towards Thionville were originally in masonry, 1 m 50 thick, and pierced by doors and windows. This layout allowed especially for an irreversibility of the fortifications in giving the Germans artillery the possibility of easily breaking down these facades and of making occupation impossible in the event of capture by the enemy. The barracks and guns were surrounded by infantry parapets, shelter posts and had light observation posts for infantry. There was also a network of barbed wire 30 m thick, surveyed by sentry-boxes. Deep underground galleries linked up all the defended localities of the Fort and were in good working order to defend the interior with iron grids, armoured doors and mines. Iron grids for defence assured the protection for the nearly area behind the barracks and guns, while at the back of the Fort, an isolated blockhouse equipped with grid iron doors surveyed the breach from which the approach road crossed the barbed wire.

From 1912 onwards, the Germans undertook a new series of extension works and reinforcements, because of the political tension and the progress made by the artillery. A second barbed wire compound was built. It was flanked by six powerful blocks of contra scarp for machine guns equipped with sheltered infantry look-out posts and electric searchlights. At the north end of the Fort a new line of infantry trenches was made in reinforced concrete with three additional picket shelters. The facades at the back of the barracks and the guns were lined with a layer of reinforced concrete and the windows were replaced by iron-clad slits for firing. At this period, the Germans also put the intervals between the forts of the region into sound working order by fortifying the countryside with numerous shelters, blockhouses and gun positions. This work continued until 1916, when central heating was installed in the Fort.

In the 1930ies, the French army made the Fort a part of the Maginot Line (The Fortified Sector of Thionville, one of the most powerful of the system), as a logistics back-up to the second line. In order to carry out this new mission, short canons of 105 mm were replaced by long ones of the same calibre, taken from the forts in Metz. The range of the artillery had now grown from 9700 m to 12700 m.


German garrisons: from 1909 to 1910, the 8th Regiment of Foot Artillery (Fussartillerie); from 1913 onwards, the 16th Regiment of Foot Artillery.

French garrisons: from 1939 to 1940, drafts of the 16th Regiment of the Fortress Infantry and of the 151st Regiment of the Position Artillery.