The peak is a pyramidal rocky spur in the Vosges mountains, about 5 km (3.1 mi) north of Thann, standing at 956 m (3,136 ft) and overlooking the Alsace Plain, Rhine valley and the Black Forest in Germany.

A few border skirmishes took place after Germany declared war on France; after 5 August, more German patrols were sent out as French attacks increased.

[1] The French VII Corps (Général Louis Bonneau) comprising the 14th and 41st divisions, advanced from Belfort to Mulhouse and Colmar 35 km (22 mi) to the north-east, suffered supply difficulties but seized the border town of Altkirch, 15 km (9.3 mi) south of Mulhouse, with a bayonet charge.

The Armée d'Alsace began the new offensive against four German Landwehr brigades, which fought a delaying action as the French advanced from Belfort, two divisions on the right passing through Dannemarie at the head of the valley of the Ill river.

In the afternoon the 66e Division attacked, taking the peak and trenches at Hirtzstein to the north-west of Wattwiller as German reserves established a new front line on the eastern slopes.

[13] The French 152e Régiment was almost annihilated, suffering 1,998 casualties from 21 to 22 December, along with Serret who was mortally wounded, the Germans taking 1,553 prisoners.

[14] On the afternoon of 24 December, Landwehr Brigade 82 tried to re-gain the lost trenches at Hirtzstein, with the assistance of flame thrower teams but achieved only a partial success.

The original front line was restored and on 8 January, Landwehr Brigade 187 re-captured the trenches at Hirzstein that had been lost on 21 December.

[15] The fighting from 20 December 1915 to 8 January 1916 cost the French 7,465 casualties, about 50 per cent of the attacking force, of whom 1,103 were taken prisoner, along with thirty machine-guns.