In 555, he seized power after a coup against his superior, the general Wang Sengbian, and in 557 he forced Emperor Jing of Liang to abdicate the throne to him, thereby establishing the Chen dynasty.

His family traced its ancestry to Chen Shi (陳寔), a county magistrate and Confucian scholar during the Han dynasty.

In the late 530s, when Xiao Ying (蕭映) the Marquess of Xinyu, a nephew of Emperor Wu, was the governor of Wuxing Commandery, he had the chance to see Chen Baxian and was impressed by him.

In 541, the people of Giao Châu Province (in modern northern Vietnam), dissatisfied with the cruel rule of Xiao Zi (蕭諮) the Marquess of Wulin (another nephew of Emperor Wu), rebelled under the leadership of Lý Bôn.

In January 544, Lý Bôn proclaimed himself emperor and named the country Vạn Xuân, ending the Second Chinese domination of Vietnam.

On the way, while he was still at Dayu Mountain (大庾嶺, on the borders of modern Jiangxi and Guangdong), he was ordered to rendezvous with the new governor of Giao Châu Province, Yang Piao (楊瞟), and another nephew of Emperor Wu's, Xiao Bo (蕭勃), to attack Lý Bôn.

In summer 548, Hou Jing, formerly a general of Eastern Wei (a branch successor state of Northern Wei) whose defection Emperor Wu had accepted, rebelled, and in 549 captured Jiankang, taking Emperor Wu and his son and crown prince Xiao Gang hostage.

For the next year, Chen advanced north through modern Jiangxi, fighting the various local warlords and generals loyal to Hou, with his main struggle against Li Qianshi (李遷仕).

By fall 551, he had rendezvoused with Xiao Yi's main general, Wang Sengbian, at Xunyang (尋陽, in modern Jiujiang, Jiangxi).

Wang put Chen in charge of the important city Jingkou (京口, in modern Zhenjiang, Jiangsu).

For the next two years, Chen was several times involved in border battles against Northern Qi (Eastern Wei's successor state).

In 554, Western Wei launched a major attack on Jiangling, and Emperor Yuan summoned Wang to come to his aid, putting Chen in charge of Jiankang.

in fall 555, believing reports that Northern Qi was going to attack, Wang sent his secretary Jiang Gan (江旰) to Jingkou to alert Chen.

Meanwhile, Xu and Ren, aided by Northern Qi, made a surprise attack on Jiankang, nearly capturing it, but were repelled by Chen's general Hou Andu.

Most officials advocated peace, and Chen, despite his skepticism about such a peace holding, agreed, and sent his nephew Chen Tanlang (陳曇朗), Emperor Yuan's grandson Xiao Zhuang the Prince of Yongjia, and Wang Min (王珉), the son of the key official Wang Chong (王沖), as hostages, permitting Northern Qi forces to withdraw, and Xu and Ren withdrew with them.

Wang Sengzhi fled to Northern Qi, and the capital region was largely under Chen Baxian's control.

[3] At the same time, Wang Lin, who controlled modern Hunan and eastern Hubei, suspicious of Chen's intentions, refused his summon to Jiankang and prepared for battle instead.

Meanwhile, news that Emperor Wu had accepted the throne had reached the front where Zhou Wenyu and Hou Andu were engaging Wang Lin, greatly depressing Zhou and Hou's forces, as this removed a major appeal that they had—that Wang was being a rebel for refusing to follow Emperor Jing's orders.

Not able to make progress in his campaign against the new Chen state, Wang sought help from Northern Qi and requested that it return Xiao Zhuang to be emperor.

Empress Zhang, after consulting the officials Du Leng (杜稜) and Cai Jingli (蔡景歷), chose not to announce Emperor Wu's death and summoned Chen Qian back from Nanhuan.