The Hundred Regiments Offensive or the Hundred Regiments Campaign was a tactical campaign initiated by the Eighth Route Army, led by the Chinese Communist Party, against the Japanese invasion in North China from 20 August 1940, to 24 January 1941. The operation was named in recognition of the involvement of 105 regiments and represented the most extensive and protracted offensive by the Eighth Route Army in Japanese-occupied territory since the onset of the countrywide War of Resistance. The campaign aimed at undermining the Shijiazhuang–Taiyuan railway, a significant line under Japanese dominion, and spanned several crucial transportation corridors in North China, occurring in three distinct periods. The operation secured substantial strategic advantages, inflicted a severe setback on Japan's "prison cage policy." According to the CCP's official histories, it elevated national morale, and highlighted the crucial role of the Chinese Communist Party and its military as a cornerstone in the Second Sino-Japanese War.