战国后期,赵国与秦、齐、楚、燕、韩、魏并称为“七雄”。但当赵国第四代君王赵武灵王继位之时,其形势却十分险恶,周围被齐、中山、燕、林胡、楼烦、东胡、秦、韩、魏包围,人称“四战之国”。积贫积弱的赵国多次受到邻边小国中山国侵扰,无力还击。西北部受林胡、楼烦的军事掠夺日甚,边关频频告急, In the later period of the Warring States, Zhao and Qin, Qi, Chu, Yan, Han, Wei and called “seven male.” However, when Zhao Guolin, the fourth generation king of the Zhao Kingdom, succeeded him, the situation was very sinister and surrounded by Qi, Zhongshan, Yan, Lin Hu, Loufan, Donghu, Qin, Han and Wei. country". The poor and weak country, Zhao repeatedly suffered from intrusion by the neighboring small Central Asian nation, unable to fight back. Northwest by Lin Hu, Lou troubled by military plunder even more, the border frequently anxious,