The Battle of Hartmannswillerkopf or Hartmannsweilerkopf (French: bataille du Vieil-Armand) was a series of engagements during the First World War fought for the control of the Hartmannswillerkopf peak in Alsace in 1914 and 1915. Hartmannswillerkopf is a pyramidal rocky spur in the Vosges mountains, about 5 km (3.1 mi) north of Thann. The peak stands at 956 m (3,136 ft) and overlooks the Alsace Plain, Rhine valley and the Black Forest in Germany and was captured by the French army during the Battle of Mulhouse (7–10, 14–26 August 1914). From the vantage point, Mulhouse and the Mulhouse–Colmar railway could be seen and the French railway from Thann to Cernay and Belfort shielded from German observation.