Zheng Keshuang (13 August 1670 – 22 September 1717), courtesy name Shihong, art name Huitang, was the third and last ruler of the Kingdom of Tungning in Taiwan in the 17th century. He was the second son of Zheng Jing and a grandson of Koxinga (Zheng Chenggong). He surrendered to the Qing Empire of mainland China in 1683 and lived the rest of his life in Beijing.
Zheng Keshuang was born in Chengtian Prefectureof the Kingdom of Tungning in Taiwan; the administrative centre of Chengtian Prefecture was at Fort Provintia. His father was Zheng Jing, the king of Tungning and the eldest son of Koxinga (Zheng Chenggong), the founder of Tungning. His biological mother was Lady Huang (黃氏), Zheng Jing's concubine.
When Zheng Jing was leading a campaign against the Manchu-led Qing Empire in mainland China in the late 1670s, he designated his elder son, Zheng Kezang as his heir apparent and put him in charge of Tungning's internal affairs. At the same time, he also arranged marriages between his two sons and the daughters of two of his most trusted officials: Zheng Kezang married the daughter of Chen Yonghua, while Zheng Keshuang married the daughter of Feng Xifan.
Zheng Jing returned to Tungning in 1680 from a failed campaign against the Qing Empire. In the same year, Chen Yonghua died after he was ousted from the political arena by his rivals, Feng Xifan and Liu Guoxuan (劉國軒). Zheng Jing died a year later in Chengtian Prefecture. After Zheng Jing's death, Feng Xifan allied with Liu Guoxuan, Zheng Cong (鄭聰) and others to slander Zheng Kezang in front of Queen Dowager Dong, Zheng Jing's mother. They claimed that Zheng Kezang was not Zheng Jing's biological son, and launched a coup to kill Zheng Kezang and seize power. Following the coup, a 12-year-old Zheng Keshuang was installed on the throne as the ruler of Tungning under the title "Prince of Yanping" (延平王). After his accession to the throne, Zheng Kezang rewarded the officials who supported him in the coup by granting them nobility titles. He also gave posthumous honorary titles to his ancestors.
In 1683, the Kangxi Emperor of the Qing Empire ordered Shi Lang to lead a naval fleet to attack and conquer Tungning. Shi Lang and his fleet defeated the Tungning forces, led by Liu Guoxuan, at the Battle of Penghu. After the battle, the Tungning royal court split into two factions, with one advocating war and the other advocating surrender. The "war" faction was led by Zheng Dexiao (鄭得瀟), Huang Liangji (黃良驥), Xiao Wu (蕭武) and Hong Gongzhu (洪拱柱), while the "surrender" faction was led by Feng Xifan and Liu Guoxuan. Zheng Keshuang heeded Feng and Liu's advice. On 5 July 1683, Feng Xifan ordered Zheng Dexiao to write a surrender document to the Qing Empire. About ten days later, Feng sent Zheng Keshuang to meet Shi Lang. On 13 August, Shi Lang entered Taiwan and received the official surrender.
Noble titles were given to the officers of the Zheng and the Zheng themselves. Zheng Keshuang and his family were taken to the Qing imperial capital, Beijing, to meet the Kangxi Emperor. The emperor made Zheng Keshuang a member of the Plain Red Banner and awarded him the hereditary title "Duke Haicheng" (海澄公; lit. "sea-quelling duke"). Some former Tungning military units, such as the rattan shield troops, were inducted into the Qing military and deployed in the battle against Russian Cossacks at Albazin.
Zheng Keshuang died of illness in 1707 in Beijing at the age of 37. His younger brother, Zheng Kexue (鄭克壆), was ordered by the Qing government to bury the remains of Zheng Chenggong and Zheng Jing in Quanzhou, Fujian – the ancestral home of the Zheng family. Zheng Keshuang's mother, Lady Huang, tried to seek permission from the Qing government to return their family property to them, but was refused.
Zheng Keshuang was survived by three sons: Zheng Anfu (鄭安福), Zheng Anlu (鄭安祿), and Zheng Ankang (鄭安康). The Taiwanese poet Zheng Chouyu (鄭愁予; born 1933) is a purported descendant of Zheng Keshuang.
Zheng Keshuang appears as one of the antagonists in the novel The Deer and the Cauldron by Louis Cha.