When Liu Zhiyuan founded the
Later Han in 947, Wang Jun was named commissioner of diplomatic accommodations (客省使) and accompanied general Guo Congyi (郭從義) during the latter's suppression of Zhao Siwan's (趙思綰) rebellion. Afterwards he was promoted all the way to commissioner of the northern court of palace armies (宣徽北院使) and stationed at
Ye to oversee military governor
Guo Wei's army. When the Later Han emperor
Liu Chengyou killed Guo Wei's entire family remaining in the
capital Kaifeng, he also sent agents to assassinate both Guo and Wang Jun. When the plot failed, Guo and Wang rebelled and led the troops to attack Kaifeng. Once Liu was killed, Guo was in charge of the affairs of the state, and he asked the
empress dowager to appoint Wang as the commissioner of military affairs (樞密使). Guo had invited
Liu Yun, a cousin of the late emperor, to the capital to ascend the throne, while he took his army northward to resist a
Khitan-led
Liao Dynasty invasion. Reaching Chanzhou (澶州), he was "forced" by his men, who wanted him to be the emperor, back to the capital. At this time Liu Yun had already reached
Xuzhou, and to prevent any unforeseen circumstances, Wang Jun conspired with Wang Yin (王殷) and sent a few commanders to Xuzhou to kill Liu Yun. Liu Yun was killed, and Guo became the new emperor of the
Later Zhou. ==Career under Later Zhou==