During the middle and late Warring States period, the power of the Zhao state increasingly declined, suffering repeated defeats in wars against Qi, Qin, Wei, and other states, losing troops and generals, and being forced to humiliatingly cede territory. Even the smaller neighboring states continuously sent troops to raid Zhao, yet Zhao was powerless to retaliate. In 326 BCE, King Wuling of Zhao ascended the throne. At the beginning of his reign, his father, Marquis Su of Zhao, had just died. Wei, Chu, Qin, Yan, and Qi, under the pretext of offering condolences, organized a coalition of ten thousand troops, aiming to seize Zhao. The 15-year-old King Wuling, with the help of his minister Fei Yi, calmly handled the situation, ultimately forcing the five states to withdraw their armies and saving Zhao from destruction. The young King Wuling harbored great ambitions and, learning from his pain, resolved to strive for strength and change the state's passive and vulnerable situation.
The state of Zhao was located in the north, bordering the Donghu to the east, the Xiongnu to the north, and the Linhu and Loufan tribes to the west. These tribes lived as nomadic herders, highly skilled in horseback riding and archery, and frequently raided Zhao's borders with their cavalry. Through constant interaction with these nomadic peoples, King Wuling of Zhao deeply recognized the superiority of cavalry. He said to his subordinates, "These nomadic horsemen come and go like the wind, swift and agile—how could such an army not win battles when charging across the battlefield?"
After long observation and analysis, King Wuling of Zhao discovered that the Hu people's soldiers, wearing narrow-sleeved short jackets and long trousers, were more agile and convenient in both daily life and horseback combat, whereas the Zhao army's uniforms, resembling commoners' short attire, were less suited for battle, often putting them at a disadvantage in engagements with Hu cavalry. Moreover, the Zhao forces primarily consisted of infantry and chariot troops, while the Hu used cavalry and bows in combat, making horses and arrows far more flexible and mobile compared to chariots and long spears.
King Wuling of Zhao realized that Zhao's repeated military defeats were not due to weak soldiers, but because the army's uniforms were unsuitable for cavalry, and the chariot-based warfare was outdated. The traditional Central Plains method of combining infantry and chariots no longer met battlefield needs, as chariots were heavy and effective only on flat terrain, becoming cumbersome in complex landscapes. Moreover, Zhao's army, primarily composed of infantry, could hardly match the swift and agile cavalry of nomadic tribes. To strengthen Zhao's military power, King Wuling decided to adopt the strengths of these nomadic peoples by forming a cavalry force and replacing the traditional Central Plains wide-sleeved robes with the tight-sleeved, short garments of the northern nomads, better suited for mounted combat.
King Wuling of Zhao firmly believed that reforming the military with cavalry and archery would inevitably enhance the combat effectiveness of Zhao's army and completely change the situation where Zhao was always on the defensive, but he also knew that the Central Plains states had always looked down upon the barbarian tribes, so this reform would certainly encounter very strong resistance. Therefore, to boost the people's confidence in implementing the policy of adopting barbarian clothing and cavalry archery across the state, he made a realistic and persuasive case for the benefits of this reform before issuing the decree. King Wuling of Zhao first trained a small number of people in cavalry archery, forming a small but elite cavalry force, and then led this limited cavalry north to attack the state of Zhongshan, achieving a series of victories that greatly inspired the confidence of Zhao's people. Next, he led the cavalry across the Yellow River and entered the long-time activity area of the Linhu people on the western side of the river. Throughout this process, King Wuling of Zhao fought many battles against nomadic cavalry and was never defeated.
This series of victories powerfully confirmed the superiority of cavalry, and King Wuling of Zhao's confidence in reform grew even stronger. He first consulted with his minister Fei Yi and General Lou Huan, saying, "Our state is surrounded by powerful enemies. Now I want to reform our military attire, wear the clothing of the Hu people, which is convenient for horseback archery." Fei Yi, Lou Huan, and others, who had backgrounds from the Rong and Di tribes, all strongly agreed. They analyzed Zhao's national conditions, terrain, culture, and other realities, believing that adopting Hu-style clothing and horseback archery would help end the state's internal divisions and strengthen its military power and competitiveness.
King Wuling of Zhao's uncle, Prince Cheng, along with Zhao Wen, Zhao Zao, and Zhao Jun, opposed the reform of adopting barbarian clothing, believing it would harm their own interests and arguing that the new law violated ancient traditions and would lose popular support. King Wuling of Zhao refuted their views, saying: "A sage acts based on actual circumstances, adapting measures to local conditions and adopting appropriate strategies. As long as it benefits the prosperity of the state, why must one rigidly adhere to the old laws of the ancients?"
King Wuling of Zhao was determined to incorporate the northwestern ethnic minorities into Zhao's territory, so he decided to adopt a strategy of using the barbarians to control the barbarians. Overcoming opposition from conservative forces and dismissing widespread dissent, he resolutely issued the "Hu clothing and cavalry archery" decree. The core content of this decree was to wear the clothing of the Hu people, which included narrow-sleeved short jackets, leather boots, leather belts with golden hooks, and military caps adorned with sable tails and cicada-patterned decorations.
King Wuling of Zhao took the lead in wearing nomadic-style clothing, completely changing the uniforms of the Zhao army to this style. Once fully equipped, he began training his soldiers in horseback riding and archery, conducting practical exercises through hunting activities.
The nobles of the Zhao state had not expected King Wuling of Zhao to be so resolute in his reforms, so they spread rumors, saying, "King Wuling of Zhao has always looked down on us, and now he is using this opportunity to humiliate us." Upon hearing this, King Wuling was furious. He summoned all the court officials, drew his bow in public, and shot an arrow that pierced the crossbeam of the gate tower, then declared sternly, "If anyone dares to spread rumors and obstruct the reforms again, that crossbeam will be their fate!" Realizing that the matter could no longer be stopped, the nobles dared not speak out in opposition again.
King Wuling of Zhao carried out a thorough reform by ordering the adoption of nomadic-style clothing. He decreed that not only soldiers but also all officials and commoners throughout the state must wear this attire. Leading by example, King Wuling himself appeared before his ministers in nomadic dress and sent an envoy to his uncle, Lord Cheng, urging him to do the same. The envoy reported that Lord Cheng was unwilling. King Wuling then personally visited his uncle, patiently persuading him until Lord Cheng was convinced and began attending court in nomadic clothing. When the Zhao royal clan and nobles saw that Lord Cheng had accepted the change, they all followed suit. Thus, nomadic-style clothing became widespread throughout Zhao.
After adopting the barbarian-style clothing, the State of Zhao established an army primarily composed of cavalry, and the convenience of this attire immediately demonstrated its effectiveness in battle. Zhao defeated its long-time rival, the Zhongshan State, seized the territories of the Linhu and Loufan tribes, expanded its territory northward by over a thousand li, and grew increasingly powerful militarily. It established administrative regions in Yunzhong, Yanmen, and Dai Commandery, extending its jurisdiction to the present-day Hetao region.