(commander of the 385th Brigade of the 129th Division) conducted combat mobilization in battle preparation.|thumb The Japanese North China Area Army estimated the strength of communist regulars to be about 88,000 in December 1939. Two years later, they revised the estimate to 140,000. On the eve of the battle, the Communist forces grew to 200,000 to 400,000 men strong, in 105 regiments. By 1940, growth was so impressive that Zhu De ordered a coordinated offensive by most of the communist regulars (46 regiments from the 115th Division, 47 from the 129th, and 22 from the 120th) against the Japanese-held cities and the railway lines linking them. According to the Communist Party's official statement, the battle started on 20 August.
First Phase (20 August – 10 September 1940) On the night of August 20, the Eighth Route Army initiated a synchronized offensive spanning thousands of kilometers along the North China front. Gunfire and explosions abruptly resonated along the Shijiazhuang–Taiyuan Railway; signal flares illuminated the night sky as the primary units of the Eighth Route Army, aided by local militias, assaulted Japanese fortifications, railway stations, and bridges. Forces from the
Jin-Cha-Ji Military Region executed an offensive from three flanks: the right contingent seized the pivotal
Niangzi Pass and obliterated a railway bridge; the central contingent conducted an unexpected assault on the
Jingxing coal mine (), collaborating with miners to entirely dismantle the mining infrastructure, thereby suspending operations for more than six months; the left contingent undermined the railway connecting
Weishui and Shijiazhuang. In the intense confrontation at Jingxing, Eighth Route Army soldiers confronted enemy fire and utilized doors and blankets to shield electric fences, sacrificing their lives to provide a passage for their army to progress. Simultaneously, the 129th Division won swift victories along the western segment of the Shijiazhuang–Taiyuan Railway. The left wing secured multiple stations, including
Lujiazhuang,
Shanghu, and Mashou, but the right flank captured
Sanzhang and
Yanzigou, demolishing several railway bridges. The 14th Regiment secured the elevated position at
Shinaoshan to facilitate railway sabotage operations, successfully defending it against multiple assaults by Japanese forces from
Yangquan. During the six-day confrontation, the men subsisted on black beans, corn husks, and vegetable soup, successfully repelling numerous Japanese attacks and eliminating over 400 adversaries. Simultaneously, the 120th Division initiated offensives along the northern segment of the
Datong–Puzhou railway, severing several sections of railway and road, therefore successfully obstructing Japanese reinforcements from accessing the Zheng-Tai Line. On 21 August, the 8th Company of the 25th Regiment, 1st Death-Defying Column, was ambushed by Japanese forces at Daluopo Village (大落坡村). The soldiers engaged in intense hand-to-hand combat, killing more than 40 Japanese soldiers, including a platoon leader, effectively shattering the myth that the Eighth Route Army could not match Japanese troops in bayonet fighting. For their valor, the company was awarded the honorary title of “Bayonet Combat Hero Company” () by Eighth Route Army headquarters. The original campaign plan specified the deployment of 22 regiments; however, the considerable excitement among participating units resulted in a swift growth to 105 regiments, totaling about 200,000 troops. On August 26, leaders Peng Dehuai and Zuo Quan officially designated the operation as the “Hundred Regiments Offensive.” Within 20 days, the Eighth Route Army accomplished its goal of “leaving no rail, sleeper, station, bunker, or bridge intact,” therefore incapacitating the whole Zheng-Tai Railway. According to internal record, losses of the Japanese First Army in the first phase amounted to 199 (including 9 officers) killed, 283 (including 15 officers) wounded, and 9 (including 1 officer) missing. It claimed 4,880 abandoned enemy corpses and 263 enemy soldiers captured.
Second Phase (September 22 – Early October 1940) . On 22 September the Eighth Route Army HQ issued directives to commence the second phase of the assault, concentrating on seizing Japanese strongholds situated along critical transportation corridors and within the central zones of the anti-Japanese base regions. In the
Jin-Cha-Ji Military Region, soldiers initiated the
Laiyuan–Lingqiu Campaign, aiming to neutralize Japanese positions in the
Laiyuan and
Lingqiu regions. In the
assault of Dongtuanbao, the Eighth Route Army obliterated the Japanese Non-Commissioned Officers' Training Battalion and captured this strategically significant site. Simultaneously, the 129th Division executed the
Yushe–Liaoxian Campaign, focusing on fortified positions along the Yushe–Liaoxian highway. During these arduous offensives, soldiers progressed under severe artillery bombardment, excavating communication trenches with shovels and pickaxes to reposition themselves within mere dozens of meters of Japanese bunkers. A significant number of demolition personnel perished in combat during these valiant assaults. The 120th Division once more focused on the northern segment of the
Tongpu Railway, hindering Japanese attempts to restore vital trade routes. At this point in the campaign, Japanese forces had grown more alert, depending on fortified defenses and employing
chemical warfare to counter the onslaught.
Third Phase (6 October 1940 – 24 January 1941) directed the battle from an artillery observation post on the Guanjia'nao front line. In early October, the Japanese army mobilized tens of thousands of troops to launch retaliatory "sweep" operations across the anti-Japanese base areas in North China. These operations were marked by the brutal implementation of the purported "
Three Alls Policy"—burn all, kill all, loot all. In response, the Eighth Route Army shifted to counter-sweep operations, relying on mobile guerrilla tactics to wear down the exhausted enemy forces. During the
Battle of Guanjianao, commander
Peng Dehuai personally arrived at the front line, only 500 meters from the enemy, to direct operations. A fierce and bloody struggle ensued between Eighth Route Army forces and Japanese troops. Peng Dehuai led the 386th Brigade of the 129th Division, 25th and 38th Regiments of the 1st Death-Defying Column, New 10th Brigade, and units directly under the headquarters to besiege the roughly 500-strong Okazaki Detachment under the 4th Independent Mixed Brigade on 29 October. After two days and nights of fierce fighting, the Chinese Army had to retreat due to the arrival of Japanese reinforcements. The Okazaki Detachment was relieved on 1 November but not before Lieutenant Colonel Okazaki was killed in action. The Eighth Route Army suffered heavy casualties in this battle. The 25th and 38th Regiments, as the main attacking forces, lost 500 men and another 1,570 were wounded. This is contrary to the CCP's claim that most combatants of the Detachment have been wiped out in the battle. Kuomintang records, including a telegram from
Wei Lihuang to
Jiang Jieshi, appeared to corroborate the CCP's claims. General Peng himself was said to have later considered Guanjianao to be one of the four major defeats in his military career. The counter-sweep operations lasted until January 1941. Although the Eighth Route Army inflicted significant casualties on the Japanese, the anti-Japanese base areas suffered heavy losses. In regions such as the
Taihang,
Taiyue, and northwest Shanxi, Japanese forces carried out widespread burning, looting, and killing in an effort to destroy the basic living conditions of the military and civilian populations in the liberated zones. ==Casualties==