In mid-December 1916 there was a deep drop in temperature with a heavy frost, making it impossible to move through the now frozen bog and gain access to the German fortifications.

The attack began early morning 23 December (5 January) and surprised the Germans, who expected that Russian troops would be celebrating Christmas.

Wearing white winter camouflage uniforms and using the cover of a heavy snowstorm, the Latvians cut passages through the German barbed wire barriers.

Many of the soldiers could not make it to the wall and did not have a way to retreat without the Germans spotting them, thus these units chose to die from frostbite (whilst not moving) over betraying their fellow Latvian brothers.

The battle continued over the next two days with varying success, as all the Latvian units became involved in heavy fighting within the breached position and the German defence stiffened as it received reinforcements from Jelgava.

On 25 December (7 January) Russian troops launched an attack on heavily fortified sand dunes on the northern side of Tīreļpurvs.

The 2nd Latvian Rifleman Brigade attacked the position from the rear and thus finally broke the German resistance on Machine-gun Hill.

However, the commander of the 12th Russian Army was not in a position to exploit the opportunity and organize a pursuit because he had not anticipated the Latvian Rifle Brigade's victory.

In one of those counterattacks, the Latvian Riflemen were forced to attack across an open field against German machine guns and thus suffered heavy losses (especially the 3rd Kurzeme Regiment).

However, they partially fulfilled their goal, the Russians tested a new breakthrough tactic, which proved successful,[5] and they were also able to pull back part of the German forces from the Romanian front, which helped the latter avoid defeat.

[1] However, the 12th Army Command punished the Siberian Riflemen, some of whom refused to go into battle – 92 of them were brought before the war tribunal and sentenced to death, and several hundred were sent back to Siberia.