In 312, he joined his fellow general, Hu Kang (胡亢), in rebelling against Jin from Jingling Commandery (竟陵, roughly modern Jingmen, Hubei), but later killed him and assumed leadership of the rebellion.
In c.February 312,[3] in light of the Disaster of Yongjia back in July 311, Hu Kang, another general of Sima Xin, took the opportunity to gather men at Jingling Commandery and start a rebellion, declaring himself Duke of Chu.
Du Zeng had artisans to tamper with Hu Kang's personal guards' weapons before secretly enticing Wang Chong to attack.
[5] Shortly after seizing power, Du Zeng wanted to enter an alliance with the Administrator of Nan Commandery, Liu Wu (劉務).
Later that year, Wang Gong (王貢), a subordinate of the Jin general, Tao Kan, forged an order seemingly from his superior appointing Du Zeng as Grand Commander of the Vanguard.
Du Zeng had many cavalry units, and after secretly opening the city gates, they quickly broke through Tao Kan's formation.
Following the battle, Du Zeng's generals gathered at Shunyang (尋陽, in present-day Xunyang, Jiangxi) where they saluted Tao Kan before leaving.
Tao Kan sent a letter to Xun Song warning him not to trust Du Zeng due to his untrustworthy nature.
The general, Zheng Pan (鄭攀), led 3,000 soldiers to join up with Du Zeng at Yunkou (溳口; southeast of present-day Xinzhou District, Hubei).
Zhao You and Zhu Gui fought Du Zeng at Lake Nüguan (女觀, in present-day Zhicheng, Hubei) but the two were killed in battle.
[11] Du Zeng pressed on to Miankou (沔口, in present-day Hankou, Hubei), so Sima Rui responded by sending Zhou Fang to deal with him.
800 of Zhou Fang's elite troops violently charged into Du Zeng's lines, killing and scattering them by the thousands.