Fortified Sector of Haguenau

The Fortified Sector of Haguenau (Secteur Fortifiée de Haguenau) was the French military organization that in 1940 controlled the most easterly section of the Maginot Line, to the north of Strasbourg. The left (western) wing of the Haguenau sector adjoined the Fortified Sector of the Vosges, includes two of the largest Maginot fortifications, Ouvrage Hochwald and Ouvrage Schoenenbourg. The right wing, started after 1931, was progressively scaled back in order to save money during the Great Depression, abandoning plans for four petit ouvrages and substituting casemates. The sector's northern and eastern sides bordered on Germany. To the south the sector borders the Fortified Sector of the Lower Rhine, from which it received several casemates in a boundary shift in 1940.

The SF Haguenau was attacked in 1940 by German forces in the Battle of France. The sector successfully fended off German assaults before the Second Armistice at Compiègne. The positions and their garrisons finally surrendered on 1 July 1940. The sector saw action again in 1944 and 1945 as American forces advanced into Alsace. The sector's easternmost sections saw heavy fighting in January 1945 during the German Operation Nordwind offensive. Following the war some positions were reactivated for use during the Cold War, with continued use of Ouvrage Hochwald as an air defense command center to the present day. Ouvrage Schoenenbourg has been preserved as a museum and is open to the public, as well as the Casemate d'Esch.

The Haguenau sector was part of the larger Fortified Region of the Lauter, a strongly defended area between the Sarre to the west and the Rhine valley to the east. The Lauter region was more important during the planning and construction phase of the Maginot Line than it was in the operational phase of the Line, when the sectors assumed prominence. The Fortified Region of the Lauter was dissolved as a military organization on 5 March 1940, becoming the 43rd Fortress Army Corps.

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