His reign was famous for one important event: the reforms consisting of "Wearing the Hu (styled) Attire and Shooting from Horseback (in battle)" (胡服騎射).

The son of Marquess Su, King Wuling ascended to the throne at 325 BCE, about halfway into the Warring States period of Chinese history.

However, in 318 BC, Zhao suffered a great defeat in the hands of Qin, causing Wuling to muse that since he did not have the power of a king, he should not use the title.

The northern expedition was highly successful: the kings of the Loufan and Linhu surrendered and their territories became administered by a governor of Dai.

King Wuling took control of their armies and added them to his military, creating extra divisions made up entirely of indigenous and hardy nomadic warriors.

He remained the de-facto ruler and called himself the "Lord Father" (Zhufu, 主父), a title similar to the Taishang Huang of later Chinese dynasties.

In 295 BCE, while King Wuling was touring Shaqiu (沙丘) in present-day Guangzong county, Wuling's older son Zhao Zhang (趙章) rebelled against King Huiwen in Handan but got defeated by forces led by Prime Minister Lord Cheng and his subordinate Lord Fengyang, also known as Li Yu (李兌).

Afraid that he would be punished for laying siege to Shaqiu, Li Yu ordered the palace to be deserted and locked King Wuling inside the compound, allowing no food or water to be provided.