During the Song Huizong period, that is, at the beginning of the12nd century, the Northern Song Dynasty declined gradually, while the Jurchen nationality in the northeast of China grew stronger. When Agu of Nuzhen Hongyan Department was appointed as the commander-in-chief, Ma Zhuang was a strong soldier. 1 1 15 years, akuta established the state of Jin. After the Liao Dynasty was destroyed, the Jin regime took the Northern Song Dynasty as its next goal and sent troops south to attack the Song Dynasty in order to unify the world. At that time, the Northern Song Dynasty had accumulated many disadvantages, such as political corruption and military weakness. 1 120 years, the Northern Song Dynasty signed the Maritime Alliance with the newly established Jin Dynasty, stipulating that two * * * would destroy Liao * * and carve up Liao territory. However, the corrupt military forces in the Northern Song Dynasty were extremely weak and had little fighting capacity. Although the 300,000 troops in the Northern Song Dynasty only attacked the remnants of the Liao army, they failed to seize the land of the Liao Dynasty in the end, which made the rulers find out the details of the Northern Song Dynasty. In the first year of Jingkang (A.D. 1 126), Jin Jun took only 40,000 people south, and all the way, like nobody's business, even broke the twenty-seven states of the Northern Song Dynasty, with soldiers pointing to the capital of song dynasty, the north bank of the Yellow River and the Song Dynasty trapped. The Northern Song Dynasty imperial court wanted to use the natural barrier of the Yellow River to resist the enemy of the nomads from the Yellow River, but Song Jun, which was guarding the south bank of the Yellow River, was short of soldiers for a long time. Occasionally, most of the soldiers in the camp are lazy and can't fight at all. At that time, although Song Jun burned the Yellow River pontoon bridge, the ferries on both sides of the strait were not completely confiscated due to the delay of subordinates' dereliction of duty. In just a few days, 8 Jin Jun assembled enough ferries on the north shore, and in October Ding Mao crossed the Yellow River. When the defenders of the Northern Song Dynasty saw that the nomads were defeated without fighting, they fled in all directions. The next day, eight 8 Jin Jun soldiers occupied Zhongmou post, a military stronghold north of the capital of song dynasty, without bloodshed. In the Northern Song Dynasty, from the emperor down to the petty officials, all panicked and messed up, and the Jin army besieged the capital of song dynasty for more than a month. Before Tokyo was broken, the royal family in the Northern Song Dynasty was ready to surrender, but the lower military and civilians in Kaifeng persisted in resisting, and 300,000 people were determined to participate in the war. Qinzong personally went to Jinying to beg for surrender, and surrendered in a grovelling manner. He also ordered Wang Bing to stop marching towards Kaifeng, and even suppressed the soldiers and civilians who spontaneously organized themselves to prepare for resistance. The people in Kaifeng suffered a great disaster because of the extensive search by the Jin army. In February of the following year, 8 Jin Jun wiped out the people of Song Huizong and Song Qinzong, and made Zhang Bangchang, the former prime minister of the Song Dynasty, a pseudo-emperor. In April, Jin Jun began to evacuate more than 3,000 captured emperors and queens, princes, royalty and nobles, together with a large number of precious seals, clothes, utensils, ritual vessels and armymen. Song Dynasty left this shameful and humiliating "Jingkang Change" in history.