In early 1915, the German infantry division began its switch to a triangular structure: three regiments per division, plus one field artillery regiment. A brigade-level staff remained, but the division and battalion essentially became the only two tactical levels of command, all others being primarily administrative. 

Other changes: machine gun companies became subordinate to the battalion and Jaeger battalions were reorganized into regiments. Cavalry regiments had become overtaken by events. Overall divisional strength decreased to about 9000, but there was a doubling of machine gun, howitzer and mortar power. The division was now much more flexible, becoming the model for all major armies over the next 20 years.