King Zhaoxiang of Qin
In 293 BC, East Zhou decided to ally itself with the states of Han and Wei, and sent troops to help attacking Qin. However, the combined forces of this alliance was destroyed at Yique by the young Qin general Bai Qi, with 240,000 men killed and their commander Gongsun Xi (公孫喜) captured and executed. After this loss, the East Zhou was unable to actively participate in future interstate struggles in any significant fashion.
In 256 BC, Duke Wu of West Zhou (西周武公) allied with other states to stop the Qin offensive on the Han city of Yangcheng. In retaliation, King Zhaoxiang of Qin sent general Jiu to invade West Zhou, successfully breaking into Wangcheng. The Duke Wu was taken to Xianyang to beg for mercy, conceding all his lands. Both King Nan and Duke Wu would die later that year, and the subsequent Duke of West Zhou, Duke Wen (西周文公), was exiled to Danhuju (憚狐聚). Because the Zhou royal court had fallen from power and King Nan had died without a successor, the Eastern Zhou Dynasty collapsed, ending 879 years of Zhou monarchy. The remaining East Zhou state was also conquered by Qin chancellor Lü Buwei seven years later in 249 BC during the reign of King Zhaoxiang's grandson King Zhuangxiang, after Duke Jing of East Zhou attempted to form an anti-Qin alliance with other states.
King Zhaoxiang of Qin
Wang Ling's attack on Handan did not go well due to the fierce Zhao resistance, and King Zhaoxiang again decided to invite Bai Qi to command the siege, but Bai Qi again advised him that Qin had a very low chance of winning this campaign. King Zhaoxiang was unhappy to hear Bai Qi's counsel, so he replaced Wang Lin with Wang He and continued the siege. In 257 BC, the Qin army was suffering losses inflicted by reinforcements from the states of Chu and Wei. King Zhaoxiang then personally visited Bai Qi and attempted to coerce him into taking the command position with royal authority. When Bai Qi once again advised abandoning the siege, King Zhaoxiang was so angry that he stripped Bai Qi's titles and exiled him. Fan Ju then falsely accused to King Zhaoxiang that Bai Qi was cursing the King behind his back, so King Zhaoxiang decreed the forced suicide of Bai Qi. This did not improve the situation for the Qin offensive, and the Qin sustained heavy casualties under the combined assault of Wei, Chu and Zhao, and the Qin army was routed and went into a general retreat. The three-state alliance then pursued and attacked Qin, reinforced by the Han army that had recently joined them. The combined forces recaptured Hedong, Anyang, Taiyuan, Pilao, Wu'an, Shangdang and Runan. The Qin expeditionary force lost most of its men in the retreat. King Zhaoxiang's ignoring of Bai Qi's advice had sown bitter fruits at the end.