He took shelter under the warlord Liu Yao but betrayed him later and seized control of Yuzhang Commandery (around present-day Nanchang, Jiangxi).
Zhao Yu (趙昱), the Administrator of Guangling Commandery, treated Ze Rong like an honoured guest.
When Ze Rong noticed that Guangling Commandery was abundant in wealth and resources, he lured Zhao Yu into a trap and killed him when he was drunk.
In 195, Liu Yao lost his base to the warlord Sun Ce, who was on a series of conquests in the Jiangdong region.
At the time, Zhou Shu (周術), the previous Administrator of Yuzhang Commandery, had died of illness so his office was vacant.
Liu Biao, the Governor of Jing Province, supported Zhuge Xuan to be the new Administrator, but that became a problem because the Han imperial court had appointed Zhu Hao to succeed Zhou Shu.
After driving Zhuge Xuan away, as Xu Shao foresaw, Ze Rong killed Zhu Hao and took control of Yuzhang Commandery.