Dong Yi was allegedly a descendant of Dong Hu (), a notable historian of the
Jin state during the
Spring and Autumn period. He started his career as a military officer serving under the
Qin dynasty and held the position of a Commandant (). In 209 BC, the
Dazexiang uprising broke out under the leadership of
Chen Sheng and
Wu Guang and sparked off a series of rebellions against the Qin dynasty throughout China. The rebel groups claimed to be restoring the former
six states which were
conquered between 230 and 221 BC by the
Qin state, the precursor of the Qin dynasty. Zhou Wen (), one of Chen Sheng's deputies, managed to lead a vanguard force that came close to
Xianyang, the Qin capital, alarming the emperor
Qin Er Shi, who called for a meeting with his subjects to discuss how to counter the rebels.
Zhang Han, then holding the position of
Minister Steward (), suggested to the emperor to grant amnesty to the convicts serving as labourers at the
Mausoleum of the First Qin Emperor, and recruit them to serve in the Qin army. The emperor approved Zhang Han's proposal and appointed him as a general, putting him in charge of leading Qin forces to fight the rebels. Zhang Han defeated and drove back Zhou Wen, who committed suicide. The emperor then sent
Sima Xin and Dong Yi to serve as Zhang Han's deputies. The Qin forces under Zhang Han's command continued to advance eastward and destroyed Chen Sheng's rebel group. Zhang Han then led his troops to attack the
Wei rebel group, defeating them along with their reinforcements from the
Qi rebel group. After that, Zhang Han moved on to attack
Tian Rong (), the leader of the Qi rebel group, prompting Tian Rong to seek help from
Xiang Liang, the leader of the
Chu rebel group. Zhang Han then engaged Xiang Liang at the Battle of Dingtao; Xiang Liang was defeated and killed in battle. In 207 BC, when Zhang Han attacked and besieged the
Zhao rebel group at Julu, the Zhao leader
Zhao Xie () sought help from the Chu rebel group.
King Huai II, the nominal leader of the Chu rebel group, sent Xiang Liang's nephew,
Xiang Yu, to assist their fellow rebels. Xiang Yu defeated Zhang Han at the
Battle of Julu despite being heavily outnumbered. When Zhang Han sent Sima Xin to request reinforcements from
Xianyang, the emperor refused to send aid after being deceived by
Zhao Gao. Sima Xin escaped from Zhao Gao's assassins on his return journey and reported to Zhang Han that the Qin government had fallen under Zhao Gao's control. Zhang Han, along with his deputies and 200,000 troops, ultimately surrendered to Xiang Yu. After the fall of the Qin dynasty in 206 BC, Xiang Yu divided the former Qin Empire into the
Eighteen Kingdoms. Zhang Han, Sima Xin and Dong Yi were made the rulers of three of the Eighteen Kingdoms. The three kingdoms were known as the
Three Qins because they occupied the lands of the former Qin state in the
Guanzhong region. Later that year, the forces of
Liu Bang, the King of
Han, invaded Guanzhong and captured Zhang Han's kingdom in a surprise attack. Dong Yi and Sima Xin then surrendered to Liu Bang. In 205 BC during the
Chu–Han Contention, after Liu Bang was defeated by Xiang Yu at the
Battle of Pengcheng, Dong Yi and Sima Xin defected to Xiang Yu's side. The following year, Dong Yi and Sima Xin joined Xiang Yu's subordinate
Cao Jiu () in resisting an attack by Liu Bang's forces during the
Battle of Chenggao. Liu Bang managed to lure Xiang Yu's forces into an ambush near the
Si River and defeated them. Dong Yi, along with Sima Xin and Cao Jiu, committed suicide after their defeat. ==References==