1915.
1. The 42d Division occupied the lines north of Chaulnes until the end of January, 1915. On December 26, the losses of the 131st Infantry Regiment since the beginning of the campaign amounted to 87 officers and 3,233 men. (Official List of Casualties.)
2. About January 25 the 42d Division was relieved and entrained for the Eastern Front with the 31st Division (21st Army Corps).
3. Concentrated in East Prussia at the beginning of February, it formed a part of the Hindenburg Army which was to force the Russians across the frontier.
4. From the vicinity of Augustowo (Feb. 14) it advanced rapidly to the east; it reached Sopockin on the 20th, and took up its position with the 21st Army Corps on the line Sopockin-Chtabine (north of Grodno). On March 9 the violent Russian counterattacks caused it heavy losses.
Mariampol.
5. At the beginning of March the 42d Division bore to the north; it was at Kalwarjia on March 26; occupied the vicinity of Mariampol on April 2. It fought in this sector from March 29 to April 24 and remained there until August. (On Apr. 13 the losses of the first two battalions of the 131st Infantry Regiment since the 6th of February had been 1,672 men, according to the Official Casualty List. The 7th Company had only 65 men left on Apr. 7.)
Vilna.
6. Renewing its forward march, the division reached Vilna on August 30; continuing toward the east, it reached Herviaty-Vorniany on September 20, then went toward Lake Narotch, vicinity of Postavy, where the front became stable.
In the autumn the 97th Infantry Regiment was transferred to the 108th Division, a new formation.