The period of the Three Kingdoms (Wei, Shu and Wu) was approaching its end. In 263 Shu fell to the Wei, which in turn was replaced by the Jin, the dynasty of Sima Yan. Sima Yan was the son of Sima Zhao. As Emperor Wu Di of the Jin, or Western Jin (265-317), Sima Yan eventually ended the incessant state of civil discord that had torn China into warring states.
In AD 280 Emperor Wu Di of Jin appointed General Du Yu in command of an army over 200,000 strong for a campaign against Wu. To stop Du Yu's advance along the Yangtze River, the King of Wu, Sun Hao, laid barriers across the river with thick iron chains. He also had pointed devices submerged into the river to hit Du Yu's fleet.
When fleet commander Wang Rui learnt of Sun Hao's defenses across the Yangtze, he came up with a clever plan. He had his soldiers build dozens of wide rafts on which he placed straw men, dressed to resemble real soldiers, and sent some soldiers who were good swimmers to send these rafts downstream for the pointed obstacles to catch hold on them. Those good swimmers disposed of the rafts together with the obstacles, clearing the waterway. To overcome the dangerous chains, Wang Rui harnessed the power of fire. His soldiers built huge torches soaked in fuel, which they ignited when they came to each of the chains. The unrelenting flames melted down the iron so that the chains all sank to the bottom of the river. Wang Rui's fleet then captured many towns along the Yangtze.
Commander-in-chief Du Yu ensured that his army launched coordinated attacks from all fronts. While Wang Rui's fleet were advancing along the Yangtze River, his officer Zhou Zhi brought 800 soldiers across the river and approached Lexiang, a major military base of the Wu. Zhou Zhi had his soldiers wave many flags and torches on Bashan Mountain, giving the impression of a large army approaching. In the meantime, Wang Rui and Du Yu captured Wu's major cities Wuchang and Jiangling.
Du Yu decided to take advantage of his overwhelming success and march straight onto Jianye (today's Nanjing), the capital of Wu. His troops were unstoppable, crushing enemy defenses along their way.
Du Yu soon captured Moling (today's Jiangning, Jiangsu Province), the gateway to Jianye. The Wu commanders either died in the war or surrendered, leaving Sun Hao desperate for a plan. His courtier Hu Chong told him: "It is over, Your Majesty. When you cannot defeat them, I am afraid you can only j oin them."
When there did not appear to be any other way out, surrender seemed a good idea to Sun Hao, since he was still able to live on with all the luxuries he had become used to. His surrender marked the end of the old period of the Three Kingdoms, and the new reunification of China.