The Feste Prinz Regent Luitpold, renamed Group Fortification Yser after 1919, is a military installation near Metz.

The aim of Germany was to protect against a French attack to take back Alsace-Lorraine and Moselle from the German Empire.

Based on new defensive concepts, such as dispersal and concealment, the fortified group was to be, in case of attack, an impassable barrier for French forces.

The protection of the perimeter of Group Fortification Yser is provided by a set of infantry positions, fortified barracks and artillery batteries scattered over a wide area and concealed by the natural topography.

From 1899, the Schlieffen plan of the German General Staff designed the fortifications of the Moselstellung, between Metz and Thionville to be like a lock for blocking any advance of French troops in case of conflict.

[4] This concept of a fortified line on the Moselle was a significant innovation compared to système Séré de Rivières developed by the French.

The same day, the troops of General Krause took position on a line from Pagny-sur-Moselle to Mondelange, passing west of Metz by Chambley, Mars-la-Tour, Jarny and Briey.

[note 1] When hostilities resume in November 1944 after a rainy month, the soldiers of the 462th Volks-Grenadier-Division still hold firmly the forts of Metz, though supplies are more difficult under the artillery and the frequent bombings.

[8] On November 9, 1944, the Air Force sends no less than 1,299 heavy bombers, B-17s and B-24s, to drop 3,753 tons of bombs, and 1,000 to 2,000 books on fortifications and strategic points in the combat zone of IIIrd army.

[12] The objective of the German staff, which was to stall US troops at Metz for the longest possible time before they could reach the front of the Siegfried Line, is largely achieved.