The fortifications of Metz, a city in northeastern France, are extensive, due to the city's strategic position near the border of France and Germany. After the Franco-Prussian War of 1870, the area was annexed by the newly created German Empire in 1871 by the Treaty of Frankfurt and became a Reichsland. The German Army decided to build a fortress line from Mulhouse to Luxembourg to protect their new territories. The centerpiece of this line was the Moselstellung between Metz and Thionville, in Lorraine. Overview The fortifications around Metz consisted of casemates, concrete barracks, infantry strong points, and concrete batteries, equipped with rotating steel turrets (100–150 mm). Each position was surrounded by several ditches, or concrete trenches, with shelters and observation cupolas. A large barbed wire belt, defended by machine gun and rifle positions, completed the defensive system. Forts had usually several large blockhouse style barracks. These had 3-meter thick reinforced concrete roofs with 2-meter thick walls. They were partially buried under as much as of compacted earth. Tunnels connected all of the structures. The fort also had deep wide trenches, some as much as in both dimensions. They were also surrounded by a thick layer of barbed wire entanglements. Each fort had 2–4 batteries, equipped with hydraulic rotating steel turrets (100–150 mm). In the summer of 1944, only 10% of the batteries were fully operational. Most of those were in Fort Driant (Feste Kronprinz) and Fort Jeanne d'Arc (Feste Kaiserin). By November, during the battle of Metz, the German troops had managed to get about 50% of the guns operational in most of the forts listed below. These batteries were lacking range tables, missing sights and other equipment to make the guns fully operational. Below is a list of the fortifications that exist around the area of Metz. Because they switched hands quite often, the French names are listed as well as any applicable German ones. In parentheses is the construction period. Forts of the first belt The first, inner belt of fortifications were completed by the French just prior to the Franco-Prussian War and were in service during the Siege of Metz from 3 September to 23 October 1870. The forts were in a ring approximately 4 km out from the city center, and were (anti-clockwise from the south): Fort de Saint-Privat (1870) / Fort Prinz August von Württemberg (1872–1875) Fort de Queuleu (1867–1870) / Fort Goeben (1871–1890) Fort