The mountain peak was a strategic area bitterly fought for. The most severe fighting for the peak took place on 19–20 January, 26 March, 25–26 April and 21–22 December 1915.
Amongst the casualties was included General Marcel Serret, commander of the 66th Infantry Division. After about 12 months of fierce combat, both sides began to focus most of their attentions on the western front farther north. Only enough men to hold the lines were left at Hartmannswillerkopf. The lines remained relatively stable for the remainder of the war and generally only artillery exchanges took place.