Official documents exaggerate the numbers of Ming soldiers and Manchus up to 470 thousand and 60 thousand respectively. According to an estimate by Rikusenshi Kenkyu Fukyukai, the Manchu soldiers were ten thousand while the Ming armies with Yehe and Korean reinforcements were one hundred thousand.
Nurhaci adopted the interior line tactics. He defeated 10 times more enemies one by one by concentrating forces. It is worth noting that the Manchu cavalry defeated matchlock and cannon forces, so the Battle of Sarhū is often compared to the Battle of Nagashino.
Nurhaci unified all Jurchen tribes except Yehe and took a hostile attitude toward Ming. In 1618 he proclaimed seven grudges (nadan amba koro 七大恨) to Heaven and declare war against Ming. He occupied Fushun (撫順), Qinghe (清河) and other cities, and then pulled out. The death of Ming General (zongbingguan) Zhang Chengyin (張承蔭) stunned the Ming court. In 1619 he attacked Yehe to provoke Ming.
Ming eventually decided to dispatch massive expeditionary forces led by Military Commissioner Yang Hao (楊鎬). Ming planned to besiege Hetu Ala, Nurhaci's home from four routes.
|HQ||Military Commissioner Yang Hao (楊鎬)||several thousand|
|Left Wing Middle Route Force||Regional Commander Du Song (杜松) |
Regional Commander Wang Xuan (王宣)
Regional Commander Zhao Menglin (趙夢麟)
Army-inspecting Censor Zhang Quan (張銓)
|Mobile Corps Commander Xi Niansui (襲念遂) |
Mobile Corps Commander Li Jibi (李季泌)
|Left Wing North Route Force||Regional Commander Ma Lin (馬林) |
Vice-general Ma Yan (麻岩)
|Army-inspecting Censor Fan Zongyan (范宗顏)||10.000|
|Mobile Corps Commander Bao Yongcheng (寶永澄) |
|Right Wing Middle Route Force||Regional Commander Li Rubo (李如栢) |
Regional Commander He Shixian (賀世賢)
Army-inspecting Censor Yan Mingtai(閻鳴泰)
|Right Wing South Route Force||Regional Commander Liu Ting 劉綎 |
Army-inspecting Censor Kang Yingqian (康應乾)
|Mobile Corps Commander Qiao Yiqi (喬一琦) |
Gang Hong-rip (Joseon)
Under repeated requests from Ming China, Gwanghaegun commanded Gang Hong-rip to help Ming forces with ten thousand soldiers against the Manchus in 1619. However, Ming armies were crushed in the Battle of Sarhū. The Korean army under command of Liu Ting lost two-thirds of his troops at Fuca and surrendered to Nurhaci. Official Korean records say that Gwanghaegun had ordered a betrayal to Nurhaci, but it is suspected to be a defamation by the Westerners faction, who deposed the king. In 1620 almost all Korean captives were released but Gang Hong-rip, who had good command of the Manchu language, was still kept.
Frustrated with unsatisfactory reward for the coup which deposed Gwanghaegun, Yi Gwal (李适) rebelled against King Injo in 1624. He temporarily occupied Hanseong (modern-day Seoul), but was eventually crushed. Han Myeongnyeong (韓明璉), an accomplice of Yi Gwal, was also killed, but his son Han Yun (韓潤) fled to the Manchus.
Gang Hong-rip fell for Han Yun's trick and wrongly believed that his family was all killed by the government. To get his revenge on Korea, he urged the Manchus to defeat the dynasty. In 1627 he guided the Manchu army led by Amin to Hanseong and as a Manchu delegate he negotiated for a truce with Korea. Then he discovered that he was deceived about his family being killed and suffered a heartbreak. He was branded as a traitor and deprived his official rank. He was rehabilitated after his death.
In foreign affairs he sought a balance between the Ming Empire and the Manchus. Since he realized Joseon was unable to compete with the Manchu military power, he tried to keep friendly relationship with the Manchus, while the kingdom was still under the suzerainty of Ming, which angered Ming and dogmatic Confucist Koreans. However the critically worsened Manchu-Ming relatinship forced him to send ten thousand soldier to aid Ming in 1619. However, the Battle of Sarhū ended in Manchu's overwhelming victory. The Korean General Gang Hong-rip lost two-thirds of his troops and surrendered to Nurhaci. Gwanghaegun negotiated independently for peace with the Manchus and managed to avoid another war.
In 1623 Gwanghaegun was deposed by the Westerners faction (西人) with a coup. He was confined first on Ganghwa Island (江華島) and then Jeju Island (濟州島), where he died in 1641. He does not have a mausoleum like the other Joseon rulers. His burial place is unknown. The Westerners faction installed Injo as the 16th king and took pro-Ming and anti-Manchu policies, which brought two Manchu invasions.