◎ To Shoot on horses in Hu dress,referring to King Wuling of Zhao's reform consisting of “wearing the Hustyled attire and shooting from horseback in battle.”
When King Wuling of Zhao succeeded to the throne,the State of Zhao was heading toward a decline,and even small neighboring states like the State of Zhongshan often came to invade it. In order to strengthen its national power,King Wuling of Zhao launched the reform of “wearing the Hu-styled attire” and “practicing shooting from horseback” in Handan,determined to take the strengths of the Hu people to make up for the weaknesses of Zhao. After the reform,Zhao became the most powerful state second only to Qin at that time. (See the part of History,Culture and Great Names.)(https://www.daowen.com)