Starting from the Yongle era of the Ming Dynasty, the court established a command office in Northeast China to suppress the remnants of the Northern Yuan and control the Jurchen tribes living there. At that time, Aisin Gioro Mengtemu (the sixth-generation ancestor of Qing Taizu Nurhaci) of the Jianzhou Jurchens served as the Left Commander of the Jianzhou Guard under the Ming. Later, as northern tribal forces grew stronger, they invaded southward and killed Mengtemu. The Jianzhou tribe was forced to relocate south to Hetu Ala, where they gradually strengthened ties with the Central Plains, significantly improving their social productivity. It was during this period that Nurhaci became the leader of the Jianzhou tribe. In the eleventh year of the Wanli era (1583), Nurhaci inherited the title of Commander, gradually unifying the scattered Jurchen tribes. In the forty-fourth year of Wanli (1616), Nurhaci established the Great Jin (later known as the Later Jin) at Hetu Ala, adopting the reign title Tianming. He then issued the "Seven Grievances" manifesto against the Ming, openly raising an army. Because the Jianzhou forces invaded Ming borders, Emperor Shenzong appointed Yang Hao, the Left Vice Minister of War, as the Liaodong Grand Coordinator, preparing to march on Hetu Ala to eliminate Nurhaci. This set the stage for the famous Battle of Sarhu.
After months of planning, Grand Coordinator Yang Hao established his headquarters in Shenyang in February 1619 (the 47th year of the Wanli era) and ordered his troops to advance toward Hetu Ala in four separate routes, aiming to encircle and destroy the Later Jin forces. At the time, the Ming Dynasty, seeking to intimidate Nurhaci, who commanded only about 20,000 soldiers, claimed to have an army of 470,000, but in reality, they had just over 100,000. These troops were divided into four routes from north to south: the western route, led by General Du Song, advanced from Fushun Pass westward straight toward Hetu Ala; the northern route, commanded by General Ma Lin, marched from Kaiyuan through Sanchakou and Shangjianya to attack the Suzi River; the eastern route, under General Liu Ting, moved eastward from Kuandian to strike Hetu Ala from the rear; and the southern route, led by General Li Rubai, advanced from Qinghe through Yagu Pass directly toward Hetu Ala. However, due to Yang Hao's lack of military talent, his battle plan merely followed old tactics—exaggerating troop numbers to create an impression of a four-sided encirclement, hoping to intimidate Nurhaci into surrendering before battle. He failed to specify clear objectives for each route, casually approved requests from the generals to alter their plans during the campaign, and did not send advance scouts to gather intelligence on the enemy. Moreover, he did not designate a primary or secondary role for the four routes or ensure mutual support among them. As a result, when the battle began, each route fought independently across a front stretching hundreds of kilometers, making coordination nearly impossible.
On April 13th, Du Song led the Western Route Army out of Fushun Pass, arriving at Sarhu (east of present-day Fushun, Liaoning) the following day. After learning that the Later Jin was sending troops to build the Jiefan City to block the Ming army, he divided his forces into two parts: one stationed at Sarhu, and the other personally led by him to attack Jiefan City, hoping to claim the first merit of defeating Nurhaci.
Facing the siege of Ming forces, the battle-hardened Nurhaci first grasped the Ming army's strategic deployment and battle plans, correctly analyzed the situation of both sides, and then adopted the combat principle of "No matter how many routes they come, I will take only one route," concentrating the Eight Banner forces for annihilation battles, preparing to defeat the Ming army piece by piece. Considering that the other three Ming army routes would find it difficult to reach Sarhu quickly due to high mountains and dangerous waters, he took advantage of Du Song's attack on Jiepan City to personally lead the elite Eight Banner troops in assaulting Sarhu, while sending Daishan and Huang Taiji to intercept Du Song, routing the Ming forces stationed at Sarhu. Ming garrison commander Li Yongfang surrendered the city, and other Ming troops fleeing to the west bank of the Sarhu River were gradually annihilated, even the brave but reckless and stubborn Ming commander Du Song was killed. Through this battle, Nurhaci eliminated the threat from the western Ming army.
On April 15, Nurhaci moved his forces to the northern front, first routing Gong Nian's army, then attacking Ma Lin's troops stationed at Shangjian Cliff, forcing Ma Lin to flee alone to Kaiyuan, and subsequently annihilating Pan Zongyan's forces stationed at Feifen Mountain, resulting in the complete destruction of all Ming forces on the northern front.
As for Liu Ting's forces on the eastern route, they had already left Kuandian on April 10, but due to treacherous mountain paths, heavy snow blocking the passes, and occasional interception by small groups of Later Jin defenders, they had not yet reached Hetu Ala by the 16th. By this time, Nurhaci had already secured victories on the western and northern fronts, so he ordered Huerhan, Amin, Daishan, and Hong Taiji to immediately lead troops to the eastern front, assemble there, and then lie in ambush, waiting for the right moment to strike. The Ming army was completely unprepared, burning villages along the way, so when Liu Ting's forces arrived at Abudali Gang (present-day ten li south of Gabazhai Village, Yushu Township, Xinbin, Liaoning), they were caught off guard by the Later Jin army, and Commander-in-Chief Liu Ting was killed in battle. Jiang Hongli's army, stationed at Fucha, was surrounded by Daishan's forces, and Jiang Hongli, along with two-thirds of his men, surrendered. With this, the threat from the Ming forces on the eastern front was also eliminated, and Nurhaci's goal of "defeating each enemy separately" was essentially achieved.
Upon hearing the shocking news that three of his armies had been utterly defeated, Grand Coordinator Yang Hao urgently ordered Li Rubo's southern force to retreat, making it the only one of the Ming Dynasty's four invading armies to escape total annihilation, thus concluding the famous Battle of Sarhu—a historic victory where the smaller force triumphed over the larger.
In this battle, Nurhaci executed a brilliant annihilation campaign in just five days, resulting in the deaths of over three hundred Ming military and civilian officials, nearly fifty thousand soldiers, and the destruction of countless weapons and equipment. This battle was a pivotal clash determining the rise or fall of the Later Jin and Ming dynasties. That same year, the Later Jin successively captured Kaiyuan and Tieling, greatly increasing their strength. From then on, Nurhaci shifted from defense to offense, and his political ambitions grew accordingly, while Ming rule in the northeastern region began to collapse entirely.