Emperor Qin Ershihuang 秦二世皇 (230-207, r. 209-207), the Second Emperor of Qin, personal name Ying Huhai 嬴胡亥, was a son of the First Emperor 秦始皇帝 (r. 246-210 BCE) of the Qin dynasty 秦 (221-206 BCE). Although only the eighteenth son of the First Emperor, Huhai was made ruler by machinations of the leading eunuch Zhao Gao 趙高 and the Counsellor-in-chief Li Si 李斯.
His older brother Prince Fusu 扶蘇 (d. 210) had long been nominated heir, but Prince Huhai was the beloved son of the emperor and took part in his father's last inspection tour in 209 BCE. When the First Emperor died, Zhao Gao and Li Si forged a testamentary edict nominating Huhai as the heir, while Prince Fusu was ordered to commit sucide. Fusu had been known as a very human person and had remonstrated against the burying alive of various scholars ("Confucians") ordered by his father. For this venture, he had been ordered to survey the border troops of general Meng Tian 蒙恬 (d. 210 BCE) in the north. When the faked edict commanding Prince Fusu and general Meng Tian to commit suicide arrived at the court, Meng Tian tried persuading the Prince to wait and see rather than immediately obeying the order of his late father. Yet Fusu's filial heart ordered him to obey his father's command instantly, and the Prince vanished.
The plot of Zhao Gao and Li Si thus succeeded, and the young prince Huhai was enthroned. He was totally dependent of the two powerful ministers who both had power enough to have all their enemies executed. Huhai, now called the Second Emperor of Qin, also toured the empire like his father had done, and had the stone steles and rock inscriptions his father had erected, like that on Mt. Jieshi 碣石 and in Guiji 會稽, amended into a wording more placant to Zhao Gao. He also continued with the construction of the huge Epang Palace 阿房宮 and with the establishing of courier routes throughout the empire. For these works, he intensified the recruitment of corvée labourers from throughout the empire.
This aggravated the general hatred of the overburdened population against the Qin dynasty and worsened the economic situation, as countless peasants were not any more able to work their fields but had to labour in the capital.
When the first rebellion broke out, Huhai followed the suggestion of general Zhang Han 章邯 to transform the corvée labourers at Mt. Lishan 酈山, where the tomb of the First Emperor was constructed, into soldiers, and so assembled a slave army against the rebel troops. Although Li Si also proposed to slow down the time- and labour-consuming construction work of the Epang palace, the Second Emperor did not adopt this suggestion.
Instead, Zhao Gao slandered Li Si and urged to the Emperor to execute him because of treason. Only when the rebels approached the metropolitan region of Guanzhong 關中, the Second Emperor began to scrutinize the sincerity of his advisor Zhao Gao. Yet Zhao Gao was well prepared to this case, had the emperor arrested and forced him to commit suicide.
The eunuch then enthroned a prince known with the name of Ziying 子嬰 (d. 206), who was either a nephew or a cousin of the Second Emperor or a younger brother of the First Emperor. On his accession to the throne in 207, Ziying renounced the title of emperor and expressed his contentedness with the title of King of Qin. Ziying knew some eunuchs he could trust, like Han Tan 韓談, and managed to have Zhao Gao killed.
He was only king for 46 days when the army of the rebel leader Liu Bang 劉邦 reached the capital Xianyang 咸陽 (modern Xianyang, Shaanxi). Known that the dynasty's fate came to a close, Ziying rushed out the city to welcome Liu Bang and presented him the state seals and submitted to the rebel army. Liu Bang accepted Ziying's surrender.